Del Mar Photonics - Newsletter Fall 2010 - Newsletter Winter 2010

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Photonics West 2011: Presentations on infrared apps

A pilot study of the clinical application infrared neural stimulation in humans

Paper 7883E-112 of Conference 7883E
Date: Sunday, 23 January 2011
Time: 8:20 AM ?8:40 AM

Author(s): Jonathan M. Cayce, Vanderbilt Univ. (United States); Jonathon D. Wells, Lockheed Martin Aculight (United States); Jonathan D. Malphrus, Vanderbilt Univ. (United States); Chris Kao, Vanderbilt Univ. Medical Ctr. (United States); Peter Konrad, E. Duco Jansen, Anita Mahadevan-Jansen, Vanderbilt Univ. (United States)
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Infrared neural stimulation (INS) is a new approach to neural activation that relies on a pulsed infrared laser to reliably excite nerves in a non-contact, artifact-free, selective manner. These advantages of INS suggest that this new technique might improve upon current clinical care which uses electrical neural monitoring; however to study the potential of this new technique in humans, safety and efficacy must be demonstrated. A preclinical safety and efficacy evaluation of this technique was conducted in seven patients undergoing selective dorsal root rhizotomy. Results indicate that the Ho:YAG laser can efficiently stimulate human dorsal spinal roots with a safety ratio of 2:1 and with better spatial precision than clinical electrical stimulation.

Stand-off explosive detection on surfaces using multispectral MIR imaging

Paper 7945-25 of Conference 7945
Date: Sunday, 23 January 2011
Time: 5:00 PM ?5:15 PM

Author(s): Kai A. Degreif, Sven Rademacher, Petya Dasheva, Fraunhofer-Institut für Physikalische Messtechnik (Germany); Frank Fuchs, Stefan Hugger, Fraunhofer-Institut für Angewandte Festkörperphysik (Germany); Frank H. Schnürer, Wenka Schweikert, Fraunhofer-Institut für Chemische Technologie (Germany)
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We present a system for the stand-off detection of solid explosive traces and precursors on surfaces. The system consists of a widely tuneable mid-infrared laser and an uncooled thermal imaging camera. The external cavity quantum cascade laser illuminates the surface of a distant object at different characteristic wavelengths. In synchronisation with the camera a hyperspectral data cube of the backscattered radiation is generated allowing a multivariate analysis of the scene. We demonstrate how multidimensional image processing is used in order to fast and sensitively detect traces of hazardous substances such as trinitrotoluene (TNT) or pentaerythritol tetranitrate (PETN). The software classifier is trained to effectively suppress false alarms.

Flexible hollow-fiber bundle for body temperature imaging

Paper 7894-45 of Conference 7894
Date: Sunday, 23 January 2011
Time: 5:10 PM ?5:30 PM

Author(s): Yuji Matsuura, Keisuke Naito, Tohoku Univ. (Japan)
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A flexible and coherent bundle of hollow optical fibers was fabricated for infrared thermal imaging. For acquisition of thermal images, differences in the transmission efficiency among the fibers were numerically compensated to obtain high temperature resolution of 1 degree C for measuring body temperature. In a lens system with 10-fold magnification and hollow fibers of 320-micron inner diameter, the spatial resolution is around 3 mm. The hollow-fiber bundle enables observation of the surface temperature of inner organs and blood flow of the surfaces when the bundle is introduced into the human body with an endoscope.

Validation of autoLF: a platform for quantifying near-infrared fluorescent images of lymphatic propulsion in humans

Paper 7902-52 of Conference 7902
Date: Monday, 24 January 2011
Time: 4:50 PM ?5:10 PM

Author(s): John C. Rasmussen, Merrick Bautista, Gabriel Dickinson, Blake Niccum, I-Chih Tan, Kristen E. Adams, Melissa B. Aldrich, Milton V. Marshall, The Univ. of Texas Health Science Ctr. at Houston (United States); Caroline E. Fife, Erik A. Maus, Latisha A. Smith, The Univ. of Texas Health Science Ctr. at Houston (United States) and Memorial Hermann Hospital (United States); Jingdan Zhang, Xiaoyan Xiang, Kevin Zhou, Siemens Corporate Research (United States); Eva M. Sevick-Muraca, The Univ. of Texas Health Science Ctr. at Houston (United States)
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Recently, we demonstrated near-infrared (NIR) fluorescence imaging for quantifying real-time lymphatic propulsion in humans following intradermal injections of microdose amounts of indocyanine green. However computational methods for image analysis are underdeveloped, hindering the translation and clinical adaptation of NIR fluorescent lymphatic imaging. We have commenced development of AutoLF, an integrated software platform which will permit automated, near real-time analysis of lymphatic function. Prior to automation, the base algorithms quantifying lymphatic propulsion must be validated to verify their consistency with existing proof-of-concept programs. Analysis of NIR fluorescent images for ten subjects indicates that the differences between their results are not significant.

High-performance long wavelength superlattice infrared detectors

Paper 7945-63 of Conference 7945
Date: Tuesday, 25 January 2011
Time: 3:35 PM ?3:55 PM

Author(s): Alexander Soibel, David Z. Y. Ting, Cory J. Hill, Mike C. Lee, Jean Nguyen, Sam A. Keo, Jason Mumolo, Sarath D. Gunapala, Jet Propulsion Lab. (United States)
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We report our recent efforts in achieving state-of-the-art performance in antimonide superlattice based infrared photodetectors. Specifically, we report a 10um cutoff superlattice device based on a complementary barrier infrared detector (CBIRD) design. The detector exhibits a responsivity of 1.5A/W and a dark current density of 1E-5A/cm2 at 77K under 0.2V bias. In addition, we discuss the noise and gain characteristics of SL photodetectors. Direct measurements of the noise spectra of SL heterodiodes at different operational conditions reveal the absence of intrinsic 1/f noise in these structures, but shows that an additional frequency-dependent noise can be generated by side-wall leakage current.

CdSiP2 picosecond optical parametric generator

Paper 7917-20 of Conference 7917
Date: Tuesday, 25 January 2011
Time: 3:40 PM ?4:00 PM

Author(s): Olivier Chalus, ICFO - Institut de Ciencies Fotoniques (Spain); Peter G. Schunemann, Kevin T. Zawilski, BAE Systems (United States); Jens Biegert, Majid Ebrahim-Zadeh, ICFO - Institut de Ciencies Fotoniques (Spain)
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We report efficient generation of picosecond pulses in the near- and mid-infrared in the new nonlinear material CdSiP2 pumped at 1064 by a mode-locked Nd:YVO4 laser at 100 kHz repetition rate. Using single-pass optical parametric generation in 8-mm-long crystal cut for type I (e?oo) noncritical phase-matching, an average idler power of 154 mW at 6204 nm together with 1.16 W of signal at 1282 nm has been obtained for 6.1 W of pump at photon conversion efficiency of 15% and 25%, respectively. Signal pulse durations of 6.36 ps are measured for 9 ps pump pulses, with both signal and idler beams in near-Gaussian spatial profile

Non-contact detection of dry eye using a custom designed IR thermal image system

Paper 7885-2 of Conference 7885
Date: Saturday, 22 January 2011
Time: 8:30 AM ?8:45 AM

Author(s): Tai Yuan Su, National Yang-Ming Univ. (Taiwan); Ko Hua Chen, Taipei Veterans General Hospital (Taiwan); Po Hsuan Liu, Ming Hong Wu, David O. Chang, United Integrated Services Co., Ltd. (Taiwan); Huihua K. Chiang, National Yang-Ming Univ. (Taiwan)
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Dry eye syndrome is a common irritating eye disease. Current clinical diagnostic methods are invasive and uncomfortable to patients. A custom designed noncontact infrared (IR) thermal image system was developed to measure the spatial and temporal variation of the ocular surface temperature over a 6-second eye-opening period. We defined two parameters: the temperature difference value and the compactness value to represent the degree of the temperature change and irregularity of the temperature distribution on the tear film. By using these two parameters, we have achieved a linear discrimination result for the dry eye and the normal eye group; the sensitivity is 0.9, the specificity is 0.86 and the receiver operating characteristic (ROC) area is 0.91. The result suggests that the custom designed IR thermal image system may be used as an effective tool for noncontact detection of dry eye.

Breast coil for multiplanar MRI/optical spectroscopy in vivo

Paper 7892-3 of Conference 7892
Date: Saturday, 22 January 2011
Time: 8:50 AM ?9:10 AM

Author(s): Michael A. Mastanduno, Shudong Jiang, Brian W. Pogue, Keith D. Paulsen, Dartmouth College (United States)
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Image-guided optical spectroscopy was developed as a non-invasive tool to compliment MR imaging of breast cancer with functional maps of tissue physiology, prior to biopsy. Because the system cannot provide sensitivity to the entire imaging domain, a device to reposition the optical fibers efficiently to focus on suspicious regions while inside the MRI machine was designed and implemented, increasing 3D sensitivity. We present methodology for optical probe optimization for clinical use and compare results from phantom and in-vivo studies with numerical studies. This interface can utilize multi-modal synergy between MR, absorption, and fluorescence imaging for accurate spatial and functional images.

Study on extremity oxygenation assessing of hemodialysis patients based on near-infrared spectroscopy

Paper 7883B-41 of Conference 7883B
Date: Saturday, 22 January 2011
Time: 9:20 AM ?9:40 AM

Author(s): Chun-Yang Wang, National Chiao Tung Univ. (Taiwan); Ching-Cheng Chuang, National Taiwan Univ. (Taiwan); Chih-Ching Lin, Taipei Veterans General Hospital (Taiwan); Yao-Sheng Hsieh, National Chiao Tung Univ. (Taiwan); Chia-Wei Sun, National Yang-Ming Univ. (Taiwan)
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Several side effects of the hemodialysis, including low blood pressure, fatigue, chest pains, nausea, headaches and muscle-cramps, are originated by removing too much fluid rapidly. Meanwhile, it leads to reduce oxygen concentration, especially with the ipsilateral of the arteriovenous fistula. Near-infrared spectroscopy (NIRS) has been shown to be an effective tool for measuring local changes of tissue in hemodynamics. In this study, the NIRS measurements were carried out with an OxiPlex instrument (Noninvasive tissue oximeter; ISS Inc., Champaign, USA). Extremity oxygenation with three conditions during the hemodialysis, i.e., pre-dialysis, in-dialysis and after-dialysis, are all measured for physiological analysis. The experimental results indicate the muscle pain in-dialysis is caused by reduction of oxygen saturation. Thus, NIRS provides an assessment tool for helping the treatment of hemodialysis patient with muscle pain in-dialysis.

Near-infrared spectroscopy and optical frequency domain imaging for intravascular tissue characterization

Paper 7883D-76 of Conference 7883D
Date: Saturday, 22 January 2011
Time: 11:00 AM ?11:20 AM

Author(s): Christine P. Fleming, Joseph A. Gardecki, Hao Wang, Brett E. Bouma, Guillermo J. Tearney, Harvard Medical School (United States)
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Optical frequency domain imaging (OFDI) is a high resolution, high speed, depth resolved imaging modality has been used for to identify critical components related to plaque vulnerability. Near infrared spectroscopy (NIRS) has the potential to complement OFDI and improve our intravascular tissue characterization capabilities. NIRS is conducted by evaluating the attenuation of light at different wavelengths in the near-infrared spectrum, assessed by measuring light remitted from the vessel wall. We present the use of NIRS and OFDI processing on phantoms, ex vivo human aorta, and in vivo OFDI pullbacks for tissue characterization.

Comparison of three near-infrared laser wavelengths for non-invasive laser coagulation of the canine vas deferens

Paper 7883B-47 of Conference 7883B
Date: Saturday, 22 January 2011
Time: 1:20 PM ?1:40 PM

Author(s): Christopher Cilip, Nathaniel M. Fried, The Univ. of North Carolina at Charlotte (United States)
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Noninvasive laser coagulation of canine vas, in vivo, has been previously reported. This study determines dependence of vas thermal coagulation on laser wavelength. Noninvasive laser coagulation of canine vas tissue, ex vivo, was performed using three near-infrared laser wavelengths: 808, 980, and 1075 nm. Each laser delivered average power of 9.2 W, 500-ms pulse duration, pulse rate of 1.0-Hz, and a 3.2-mm diameter laser spot, synchronized with cryogen spray cooling of skin surface for a treatment time of 60 s. The 1075 nm wavelength was the only laser that consistently produced thermal coagulation of the vas without scrotal skin burns.

Quantifying thermal modifications on laser welded skin tissue

Paper 7902-10 of Conference 7902
Date: Saturday, 22 January 2011
Time: 2:15 PM ?2:35 PM

Author(s): Hasim O. Tabakoglu, Fatih Univ. (Turkey); Murat Gülsoy, Bogaziçi Univ, (Turkey)
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Laser tissue welding is a potential medical treatment method. Recovery period depends on the thermal harm given to the skin tissue. 1 cm long cuts were treated spot by spot near infrared laser applications: 809 nm, 980 nm and 1070 nm. Thermal effect can be determined under light microscope. Polarized light and phase contrast method give information about collagen structural changes on H&E stained tissue samples. Images were taken with a CCD camera and examined with imaging software. At the end of the 4-day recovery period, 1070 nm laser has given the minimum thermal damage to the tissue been observed.

Detection of chemical changes in bone after irradiation with Er,Cr:YSGG laser

Paper 7883F-132 of Conference 7883F
Date: Saturday, 22 January 2011
Time: 2:20 PM ?2:40 PM

Author(s): Carolina Benetti, Instituto de Pesquisas Energéticas e Nucleares (Brazil); Patricia A. Ana, Univ. Federal do ABC (Brazil); Moises O. Santos, Jose S. Rabelo, Denise M. Zezell, Instituto de Pesquisas Energéticas e Nucleares (Brazil)
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In this study, the Fourier Transform Infrared spectroscopy (FTIR) was used to verify the molecular and compositional changes promoted by laser irradiation on bone tissue. Bone slabs were obtained from rabbits and, after an initial analysis by ATR-FTIR spectroscopy, all samples were irradiated using a pulsed Er,Cr:YSGG laser (2780 nm), and analysed once again. It was observed that the laser irradiation promoted changes in the organic and collagen structure of bone tissue, which can interfere with the healing process. In this way, these changes should be considered in a clinical application of laser irradiation in surgeries.

Near-infrared laser treatment of complicated hemangiomas in children: ten-year clinical experience

Paper 7883A-16 of Conference 7883A
Date: Saturday, 22 January 2011
Time: 3:00 PM ?3:20 PM

Author(s): Ivan A. Abushkin, Valeriy A. Privalov, Chelyabinsk State Medical Academy (Russian Federation); Alexander V. Lappa, Chelyabinsk State Univ. (Russian Federation)
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Results of application of low invasive laser technology (developed by authors: Proc. SPIE 5863, 107-115 (2005), Russian Federation patent ?2290228 of.27.12.06) to treatment of hemangiomas in children are presented and analyzed in this work. From 2001 the technology was applied to about 1500 children with more than 2000 hemangiomas. Majority of them were complicated ones: belong to cavernous or combined types or (and) were localized on problem places: on face near eyes, nose, and lips, on auricles, on perineum near anus and genitals, in respiratory and gastrointestinal tracts. Diode laser with wavelength 920, 970, and 1060 nm at distant and interstitial irradiation were applied. In case of need there applied endoscopes. Excellent and good results have been achieved in 94% cases; there was a significant improvement in the rest cases.

In-vivo swine myocardial tissue characterization and monitoring during open chest surgery by time-resolved diffuse near-infrared spectroscopy

Paper 7883D-84 of Conference 7883D
Date: Saturday, 22 January 2011
Time: 3:40 PM ?4:00 PM

Author(s): Lorenzo Spinelli, Consiglio Nazionale delle Ricerche (Italy); Davide Contini, Andrea Farina, Alessandro Torricelli, Antonio Pifferi, Rinaldo Cubeddu, Politecnico di Milano (Italy); Luca Ascari, Scuola Superiore Sant'Anna (Italy); Luca Potí, Consorzio Nazionale Interuniversitario per le Telecomunicazioni (Italy); Maria Giovanna Trivella, Consiglio Nazionale delle Ricerche (Italy); Antonio L'Abbate, Stefano Puzzuoli, Scuola Superiore Sant'Anna (Italy) and Consiglio Nazionale delle Ricerche (Italy)
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Worldwide, a large number of patients suffering from cardiac diseases are treated by surgery. However, surgical failure can occur, due in part to the imperfect control of the heart metabolic status. This is indirectly controlled by the electrocardiogram and ultrasounds as direct measurements are lacking. Diffuse optical technologies are promising tools for biological tissue characterization. In this work we show the feasibility of the in-vivo determination of myocardial absorption and scattering spectra (600-1100 nm), and of monitoring myocardial tissue hemodynamics by time-resolved diffuse NIRS. Both measurements have been performed on beating heart during open chest surgery in pigs.

Improved cerebrovascular reactivity (CVR) mapping using concurrent fMRI and near-infrared spectroscopy

Paper 7896-4 of Conference 7896
Date: Sunday, 23 January 2011
Time: 9:10 AM ?9:30 AM

Author(s): Yunjie Tong, Blaise B. Frederick, McLean Hospital (United States)
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We demonstrate a novel method to process fMRI data obtained during blocked breath holding task (BHT) to produce accurate cerebrovascular reactivity (CVR) maps by using simultaneously collected near infrared spectroscopy (NIRS) data and its temporal shifts as regressors. In this concurrent NIRS and fMRI study, 6 healthy subjects performed blocked BHT in the scanner with the NIRS probe placed on the prefrontal area. The method produces a much more accurate CVR map compared to existing methods and offers a way to produce the comparable baseline cerebral vascular maps if applied to resting state data.

Joint attention studies in normal and autistic children using NIRS

Paper 7883E-115 of Conference 7883E
Date: Sunday, 23 January 2011
Time: 9:20 AM ?9:40 AM

Author(s): Ujwal Chaudhary, Michael Hall, Florida International Univ. (United States); Anibal Gutierrez, Daniel Messinger, Univ. of Miami (United States); Gustavo Rey, Miami Children's Hospital (United States); Anuradha Godavarty, Florida International Univ. (United States)
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Autism is marked by the inability to respond to joint attention skill task, which is used to distinguish autistic from non-autistic. Near infrared spectroscopy (NIRS) is being applied for the first time to study the brain activation and connectivity in the frontal cortex of typically developing (TD) and autistic children (4-8 years of age) in response to joint attention task. Preliminary results from TD child shows difference in brain activation during joint attention interaction compared to the non-joint interaction and rest. Similar activation study did not reveal significant differences in HbO across the stimuli in, unlike in an autistic child.

Adaptive cancellation of spontaneous fluctuations in combination with depth compensation algorithm enhances real-time brain imaging in diffuse optical tomography

Paper 7896-6 of Conference 7896
Date: Sunday, 23 January 2011
Time: 9:50 AM ?10:10 AM

Author(s): Fenghua Tian, Haijing Niu, Bilal Khan, George Alexandrakis, Khosrow Behbehani, Hanli Liu, The Univ. of Texas at Arlington (United States)
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Diffuse optical tomography (DOT) of brain function is limited by its high sensitivity to the superficial tissues and severely decreased sensitivity to the brain. Significant interference results from spontaneous fluctuations that are embedded in both the superficial tissues and brain, such as arterial pulsation and vasomotion. In this study, first we investigate coherence and phase shift of the spontaneous fluctuations within the superficial tissues and at various depths of the brain, respectively. The fluctuations originating from arterial pulsation are globally coherent, while the fluctuations originating from vasomotion tend to lose its coherence with depth. Then adaptive cancellation of the spontaneous fluctuations with a frequency-specific strategy is utilized and validated in both resting and activation states. Improved depth localization of reconstructed image is achieved by combining adaptive cancellation with a depth compensation algorithm that we recently developed.

Diet-induced alterations in brain microvasculature: a non-invasive, near-infrared spectroscopy study in rats

Paper 7896-7 of Conference 7896
Date: Sunday, 23 January 2011
Time: 10:40 AM ?11:00 AM

Author(s): Bertan Hallacoglu, Angelo Sassaroli, Irwin H. Rosenberg, Sergio Fantini, Aron Troen, Tufts Univ. (United States)
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Abstract. Deficiencies of vitamins B9 (folate), B12, and B6 are potentially modifiable predictors of cognitive impairment. We report non-invasive, near-infrared spectroscopy measurements in rats, which showed that absolute brain hemoglobin concentration ([tHb]) and oxygen saturation (StO2) were significantly lower in folate deficient animals (n=5) with respect to control animals (n=6) ([tHb]: 73?0 礛 vs. 95?4 礛; StO2: 55%?% vs. 66% ?%). These results implicate microvascular rarefaction and cognitive impairment in folate deficient rats. We will also report the results of an animal NIRS study of B12 deficiency. These studies are initial steps towards understanding vascular deficiency effects in humans.

In-vivo multiplexed optical imaging system with near-infrared emitting quantum dots and lanthanide-doped nanoparticles

Paper 7909-23 of Conference 7909
Date: Sunday, 23 January 2011
Time: 11:00 AM ?11:10 AM

Author(s): Sanghwa Jeong, Nayoun Won, Kangwook Kim, Joonhyuck Park, Sungjee Kim, Pohang Univ. of Science and Technology (Korea, Republic of)
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Multiplexed imaging provides the opportunity to investigate the complex biological phenomena governed by multiple biomolecules. Quantum dots (QDs) with different emission wavelengths can be multiplexed by single excitation light. Multiplexing between QDs and lanthanide-doped nanoparticles (LNs) can be obtained by switching the excitation sources while they emit at same wavelength domain. NIR emitting QDs and LNs were synthesized with judicious emission wavelength control by pyrolysis method to expand the multiplexing capability in 700 to 900 nm. Using small animal models, in vivo real-time multiplexed imaging will be demonstrated with QDs and LNs simultaneously and complimentarily exploited for the contrast agents.

Synthesis of 'non-toxic' quantum dots and the in-vivo imaging applications thereof

Paper 7909-24 of Conference 7909
Date: Sunday, 23 January 2011
Time: 11:10 AM ?11:20 AM

Author(s): Youngrong Park, Jiwon Bang, Nayoun Won, Sanghwa Jeong, Kangwook Kim, Sungjee Kim, Pohang Univ. of Science and Technology (Korea, Republic of)
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Near-infrared (NIR) emitting, non-toxic Quantum dots (QDs) can be a promising fluorescent marker in biological imaging applications. High quality 'non-toxic' QDs were synthesized that include InP and CuInS2 QDs. The solvent and QD precursors were judiciously chosen to obtain highly bright and stable QDs with reproducible manner. Their photoluminescence spectra were tuned down to far-red and NIR regions for bio-imaging applications. Using small animal models, real-time multiplexed in vivo imaging was demonstrated with the 'non-toxic' NIR emitting QDs. Furthermore, we will discuss penetration depths of the QD imaging along with the contrast to noise ratios and the image sharpness.

Ultrafast density- and temperature-dependent carrier dynamics in a quantum dots-in-a-well heterostructure

Paper 7937-6 of Conference 7937
Date: Sunday, 23 January 2011
Time: 11:10 AM ?11:35 AM

Author(s): Rohit P. Prasankumar, Los Alamos National Lab. (United States); Rajeev V. Shenoi, The Univ. of New Mexico (United States); Junji Urayama, Weng W. Chow, Sandia National Labs. (United States); Sanjay Krishna, The Univ. of New Mexico (United States); Antoinette J. Taylor, Los Alamos National Lab. (United States)
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The incorporation of semiconductor quantum dots into different heterostructures for applications in nanoscale photodetection and lasing is an active area of research. Here, we use ultrafast differential transmission (DT) spectroscopy to temporally and spectrally resolve density-and-temperature-dependent carrier dynamics in a quantum dots-in-a-well (DWELL) heterostructure. Our experiments provide essential insight into carrier relaxation across multiple spatial dimensions and reveal the influence of Coulomb interactions across different time scales and excitation densities. This is highlighted by the observed influence of the quantum well population upon light absorption at the quantum dot excited state, which has important implications for DWELL-based lasers and amplifiers.

Near-infrared quantum dots for in-vivo real-time multiplexed imaging applications

Paper 7909-25 of Conference 7909
Date: Sunday, 23 January 2011
Time: 11:20 AM ?11:40 AM

Author(s): Nayoun Won, Sanghwa Jeong, Kangwook Kim, Joonhyuck Park, Sungjee Kim, Pohang Univ. of Science and Technology (Korea, Republic of)
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Near-infrared (NIR) quantum dots (QDs) promise a new modality for in vivo bio-imaging and future medical imaging applications. We developed an in vivo real-time multiplexed NIR QD imaging system that covers the NIR wavelength range from 700 to 1700 nm. To verify the capability of our home-built imaging system for the surgical imaging applications, the penetration depth of the QD imaging was simulated using biological tissues such as bovine liver and porcine skin samples. We investigate into the imaging parameters such as excitation and emission wavelengths, fluence rates, incidence angles, and polarizations that determine contrast to noise ratios and sharpness.

Time-domain near-infrared spectroscopy monitoring of brain pathophysiology after injury, stroke, and subarachnoid hemmorhage

Paper 7896-9 of Conference 7896
Date: Sunday, 23 January 2011
Time: 11:20 AM ?11:40 AM

Author(s): Nicusor V. Iftimia, Physical Sciences Inc. (United States); Juliette J. Selb, Eric Rosenthal, Massachusetts General Hospital (United States); Mircea Mujat, Robert D. Ferguson, Daniel X. Hammer, Physical Sciences Inc. (United States)
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The knowledge of brain pathology after traumatic head injury, stroke, or subarachnoid hemorrhage (SAH) is necessary for adequate and patient-oriented treatment. While the primary insult, which represents the direct damage, cannot be therapeutically influenced, the secondary damage can be prevented by treatment. Signs of danger for secondary damage include changes in cerebral blood flow (hypo-and hyperperfusion), impairment of cerebrovascular autoregulation, cerebral metabolic dysfunction, and inadequate cerebral oxygenation. Near-infrared spectroscopy seems to be a suitable technology for monitoring such pathologies. We present the development and preliminary testing of a TD NIR system on TBI, stroke, and SAH patients. Preliminary data show the TD NIRS findings correlate well with CT findings and patient health status monitored with NICU sensors. The development of the TD NIRS instrument and its preliminary NICU testing will be discussed.

The progress of QD laser in the near IR wavelength region

Paper 7945-13 of Conference 7945
Date: Sunday, 23 January 2011
Time: 12:55 PM ?1:15 PM

Author(s): Daekon Oh, Electronics and Telecommunications Research Institute (Korea, Republic of); Jinsoo Kim, Chonbuk National Univ. (Korea, Republic of); Jinhong Lee, Korea Photonics Technology Institute (Korea, Republic of); Seungui Hong, Cheoluk W. Lee, Wonseok Han, Byung-Seok Choi, Electronics and Telecommunications Research Institute (Korea, Republic of)
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Demand on high quality and new contents in optical internet still requires continuous development of advanced optical components in the point of low cost and high performance. The use of quantum dot structure in the active region of semiconductor optical devices have been shown superior high carrier dynamic and temperature less sensitive properties by some research groups. A 1.5?m QD laser on the InP(100) substrate will be demonstrated in detail with the brief review of new achievements of QD optical devices in the near IR wavelength range. Enhanced temperature stability of Fabry-Perot QD laser will be reported compare to the QW laser. Also, 10Gbps direct modulation speed demonstrated with the moderate side mode suppression in the DFB QD laser. Statistic approach for the reproducible formation of quantum dot in the MOCVD and MBE system also will be introduced in this talk.


Repeatability of end-expiratory breath hold responses measured with near-infrared spectroscopy

Paper 7896-12 of Conference 7896
Date: Sunday, 23 January 2011
Time: 1:50 PM ?2:10 PM

Author(s): Jaakko Virtanen, Aalto Univ. School of Science and Technology (Finland); Tommi Noponen, Univ.of Turku (Finland); Risto Ilmoniemi, Aalto Univ. School of Science and Technology (Finland)
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Near-infrared spectroscopy (NIRS) can be used to assess the cerebrovascular response to CO2 during breath hold. We measured 8 healthy subjects during voluntary end-expiratory breath hold to study inter- and intraindividual variability of the deoxy- and oxyhemoglobin (HbR and HbO2, respectively) response curves for the scalp and cerebral cortex. Although cortical [HbO2] behaves qualitatively similarly in all subjects, there is large inter- and intraindividual variability, and in the case of [HbR] also qualitative variability. However, the slope of cortical [HbO2] during the breath hold has good measurement repeatability, and it is a good indicator of an individual's CO2 tolerance.

A method for fluorescence-guided surgery providing an estimate of depth in multispectral near-infrared subsurface imaging

Paper 7886-24 of Conference 7886
Date: Sunday, 23 January 2011
Time: 2:00 PM ?2:20 PM

Author(s): Frederic Leblond, Pablo A. Valdes, Dartmouth College (United States); Anthony Kim, Ontario Cancer Institute (Canada); Scott C. Davis, Zaven Ovanesyan, Venkataramanan Krishnaswamy, Dartmouth College (United States); Brian C. Wilson, Ontario Cancer Institute (Canada); Alexander Hartov, Brian W. Pogue, Keith D. Paulsen, Dartmouth College (United States); David W. Roberts, Dartmouth Hitchcock Medical Ctr. (United States)
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Fluorescence-guided surgery for intracranial tumor resection relies on optical contrast from the endogenous molecule, protoporphyrin IX. We present a fluorescence-ratio detection method to localize sub-surface pathologies during surgery. An analytical derivation is presented providing a closed form expression that can be used to estimate the depth of fluorescent molecules based on the spectral deformation of near-infrared measurements. Experimental data acquired for tissue-simulating phantoms with a broad-beam non-contact multi-spectral imaging system are presented. The method has been evaluated intra-operatively for in vivo data acquisition during brain tumor resection. Results are presented and an assessment of the method provided.

Monte Carlo based modeling of indocyanine green bolus tracking in the adult human head

Paper 7896-13 of Conference 7896
Date: Sunday, 23 January 2011
Time: 2:10 PM ?2:30 PM

Author(s): Jonathan T. Elliott, Mamadou Diop, Kenneth M. Tichauer, Lawson Health Research Institute (Canada); Ting-Yim Lee, Robarts Research Institute (Canada); Keith St. Lawrence, Lawson Health Research Institute (Canada)
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Following traumatic brain injury, complications that occur are mainly due to compromised blood flow to the brain, leading to oxygen deprivation. Bedside optical techniques have the potential to improve patient care in these situations, because they can measure blood flow in the brain non-invasively using a light-absorbing dye as a tracer. However, obtaining accurate measurements from complex tissue structures like the human head is challenging. Here we describe a theoretical model that can assess the ability of these techniques to measure blood flow in a variety of clinical situations and we present the results of some numerical experiments.

A construction of standardized near-infrared hyperspectral teeth database: a first step in the development of reliable diagnostic tool for quantification and early detection of caries

Paper 7884-13 of Conference 7884
Date: Sunday, 23 January 2011
Time: 2:20 PM ?2:40 PM

Author(s): Miran Buermen, Ales Fidler, Peter Usenik, Franjo Pernu? Bo歵jan Likar, Univ. of Ljubljana (Slovenia)
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Several papers reported on near infrared spectroscopy to be a potentially useful noninvasive spectroscopic technique for early detection of caries lesions. However, the conducted studies were mostly qualitative and did not include the critical assessment of the spectral variability of the sound and carious dental tissues and influence of the water content. In order to characterize the described spectral variability, a standardized hyper-spectral database was constructed by imaging 12 extracted human teeth with natural lesions of various degrees. By analyzing the acquired spectra we were able to accurately model the spectral variability of the sound and carious dental tissues.

Continuous monitoring of absolute cerebral blood flow by combining diffuse correlation spectroscopy with time-resolved near-infrared technology

Paper 7896-14 of Conference 7896
Date: Sunday, 23 January 2011
Time: 2:30 PM ?2:50 PM

Author(s): Mamadou Diop, Lawson Health Research Institute (Canada); Ting-Yim Lee, Robarts Research Institute (Canada); Keith St. Lawrence, Lawson Health Research Institute (Canada)
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Monitoring brain blood flow is critical for optimizing recovery from neurological emergencies such as stroke and trauma brain injury. Unfortunately, a technique for continuously monitoring at the bedside has yet to be established. Our group proposes to marry two novel optical techniques to overcome this limitations: diffuse correlation spectroscopy to monitor relative flow changes and a time-resolved near-infrared method for quantifying absolute blood flow. Preliminary data demonstrated that the two techniques measured the same increase in brain blood flow, demonstrating the potential of this hybrid approach for bedside monitoring.

Opto-electrophoretic detection of bio-molecules using conducting chalcogenide glass sensors

Paper 7894-38 of Conference 7894
Date: Sunday, 23 January 2011
Time: 2:40 PM ?3:00 PM

Author(s): Pierre Lucas, Zhiyong Yang, Kelly A. Reynolds, The Univ. of Arizona (United States); Marie-Laure Anne, Bruno Bureau, Univ. de Rennes 1 (France)
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Novel telluride glasses with high electrical conductivity, wide infrared transparency and good resistance to crystallization are used to design an opto-electrophoretic sensor for detection and identification of hazardous microorgansims. The sensor is based on an attenuated total reflectance element made of Ge-As-Te glass that serves as both an optical sensing zone and an electrode for driving the migration of bio-molecules within the evanescent wave of the sensor. An electric field is applied between the optical element and a counter electrode in order to induce the migration of bio-molecules carrying surface charges. The effect of concentration and applied voltage is tested and the migration effect is shown to be reversible upon switching the electric field. The collected signal is of high quality and can be used to identify different bacterial strain through statistical spectral analysis. This technique therefore provides the ability to detect hazardous microorganism with high specificity and high sensitivity in aqueous environments. This has great potential for online monitoring of water quality.

Phasor representation of oxy- and deoxy-hemoglobin concentrations at rest and during brain activation

Paper 7896-15 of Conference 7896
Date: Sunday, 23 January 2011
Time: 2:50 PM ?3:10 PM

Author(s): Feng Zheng, Michele Pierro, Angelo Sassaroli, Sergio Fantini, Tufts Univ. (United States)
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We introduce a novel phasor representation of cerebral hemodynamic oscillations at a specific frequency as measured by near-infrared spectroscopy. We have initially focused our attention on spontaneous low frequency oscillations, typically centered at 0.08-0.10 Hz in the brain of human subjects, and used phasor notation to investigate spatio-temporal relationships of associated cerebral [Hb] and [HbO] oscillations. In our initial measurements, we have found that during rest and brain activation conditions, the low frequency oscillations of [Hb] and [HbO] feature different relative phase values. We also explore the potential of this novel analytical tool for the study of functional connectivity networks.

Acetylene measurement using quantum cascade lasers at 14祄

Paper 7945-19 of Conference 7945
Date: Sunday, 23 January 2011
Time: 2:55 PM ?3:10 PM

Author(s): Johannes Herbst, Fraunhofer Institute Physical Measurement Techniques (Germany); Benjamin Scherer, Ferdinand Singer, Jochen Erb, Armin Lambrecht, Fraunhofer-Institut für Physikalische Messtechnik (Germany); Carsten Rathke, Stefan Filip, Jürgen Kappler, ABB Automation GmbH (Germany); Peter Fuchs, Johannes Koeth, nanoplus GmbH (Germany); Jochen Friedl, Julius-Maximilians-Univ. Würzburg (Germany); Tobias Schlereth, Univ. Würzburg (Germany); J. Semmel, Sven Höfling, Lukas Worschech, Alfred W. B. Forchel, Julius-Maximilians-Univ. Würzburg (Germany)
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Monitoring of acetylene (C2H2) concentration is important for many chemical processes. Fraunhofer IPM investigated the use of quantum cascade laser (QCL) spectroscopy in the 14祄 range for a sensitive and fast specific detection of C2H2. This spectral range is favorable to avoid spectral interferences by other components which could be present in typical raw process gases. For these purpose new DFB QCLs were developed and their spectral properties were investigated. Performance characteristics determined with a laboratory setup of a new QCL gas analyzer for low concentrations will be presented.

MBE growth and characterization of dilute nitrides for mid-infrared optoelectronic devices

Paper 7945-21 of Conference 7945
Date: Sunday, 23 January 2011
Time: 3:45 PM ?4:05 PM

Author(s): Martin I. de la Mare, Tony Krier, Qian Zhuang, Peter J. Carrington, Lancaster Univ. (United Kingdom); Amalia Patane, The Univ. of Nottingham (United Kingdom)
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Dilute nitride alloys have great potential for the development of optoelectronic devices operating in the technologically important mid-infrared spectral range. We report on the epitaxy of InAsNSb dilute nitride structures which exhibit photoluminescence within the 2-5祄 wavelength region. The growth of InAsNSb is of particular interest because one can envisage producing novel type I strain balanced quantum wells on InAs substrates. The structural properties of the resulting material were studied using electron microscopy and high resolution X-ray diffraction. Detailed photoluminescence measurements were made over the range from 4-300 K to investigate the InAsNSb optical properties and luminescence efficiency.

Selective treatment of carious dentin using a mid-infrared tunable pulsed laser at 6 祄 wavelength range

Paper 7884-20 of Conference 7884
Date: Sunday, 23 January 2011
Time: 5:10 PM ?5:30 PM

Author(s): Masayuki Saiki, Katsunori Ishii, Osaka Univ. (Japan); Kazushi Yoshikawa, Kenzo Yasuo, Kazuyo Yamamoto, Osaka Dental Univ. Hospital (Japan); Kunio Awazu, Osaka Univ. (Japan) and Univ. of Fukui (Japan) and Kyoto Univ. (Japan)
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The objective of this study is to develop the laser caries treatment based on the concept of minimal intervention. From the absorption property of carious dentin, a mid-infrared pulsed laser was tuned to the wavelengths of 6.02 and 6.42 祄 which correspond to amide I and amide II. Demineralized caries-like dentin was removed selectively with less-invasive effect on sound dentin at both wavelengths. Particularly at ?= 6.02 祄, desirable ablation efficiency and surface morphology were observed. 6.02 祄 is a promising wavelength for the selective laser treatment of carious dentin.

Algorithmic depth compensation improves transverse resolution and quantification in functional diffuse optical tomography

Paper 7896-82 of Conference 7896
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Fenghua Tian, Haijing Niu, Sabin Khadka, Zi-Jing Lin, Hanli Liu, The Univ. of Texas at Arlington (United States)
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Accurate depth localization of a regional activation has been a major challenge in functional brain imaging by diffuse optical tomography (DOT) because the photon density drops rapidly with increased depth in tissue. Recently we have developed a depth compensation algorithm to improve the accuracy of depth localization in DOT. In this paper, we first present a depth-compensation-based approach to improve the quantification of absorption perturbation in DOT by defining a spatial prior. Next, we present comprehensive analysis on the spatial resolution of three-dimensional DOT without and with depth compensation. It reveals that the depth compensation algorithm improves the resolution of DOT in transverse direction. At last, we will further discuss how to improve the spatial resolution by combining the depth compensation algorithm with high-density measurement.

Combination of optical imaging with NIR fluorophore and sonogram in breast cancer diagnosis

Paper 7886-45 of Conference 7886
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Kuo-Chih Liao, Tsung-Hsien Yen, Gi-Da Lee, Yu-Hsiang Chou, National Chung Hsing Univ. (Taiwan)
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The project will evaluate the potential of the combination imaging tools (optical imaging with near infrared fluorophore, SIDAG, and sonogram) for non-invasive, low facility requirement and low cost breast cancer diagnosis. The average value of optical and echo signals from normal tissue, benign lesion xenografts (extracellular membrane extract from the EHS mouse sarcoma) and malignant tumor xenografts (MCF-7 cell) developed in nude mice will be recorded and mapped for the following procedures: 1. Average threshold value of contrasts among the normal tissue, benign lesion xenograft and malignant tumor xenograft (screening). 2. Size and boundary of tumor tissue (staging of cancer). 3. Size and boundary of tumor tissue before and after chemotherapy (evaluation of treatment).

Experimental estimation of the sensitivity profile of time-resolved reflectance measurement: a phantom study

Paper 7896-93 of Conference 7896
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Piotr L. Sawosz, Michal Kacprzak, Institute of Biocybernetics and Biomedical Engineering (Poland); Wojciech Weigl, Medical Univ. of Warsaw (Poland); Norbert S. Zolek, Stanislaw Wojtkiewicz, Roman Maniewski, Adam Liebert, Institute of Biocybernetics and Biomedical Engineering (Poland)
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We proposed a method for experimental estimation of distribution of light penetration probability in an inhomogeneous tissue-phantom. A human head phantom was constructed with the use of a skull filled with optically turbid liquid. Time-gated, intensified CCD camera was used for imaging of the phantom in the plane perpendicular to the direction of the incident light. Distribution of visiting probability of photons virtually travelling between source and detector was calculated by convolving the distributions of time of flight of photons recorded for two source positions. Influence of inhomogeneities of the skull on time-resolved distribution of light penetration probability was assessed.

Near-infrared fluorescent imaging to assess lymphatic function improvement after advanced pneumatic compression device treatment of lymphedema

Paper 7890-50 of Conference 7890
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Kristen E. Adams, Blake Niccum, Gabriel Dickinson, Merrick Bautista, John C. Rasmussen, I-Chih Tan, Chinmay D. Darne, Melissa B. Aldrich, Milton V. Marshall, Latisha A. Smith, Erik A. Maus, Caroline E. Fife, Renie Guilloid, The Univ. of Texas Health Science Ctr. at Houston (United States); Sunday Hoy, Tactile Systems Technology, Inc. (United States); Eva M. Sevick-Muraca, The Univ. of Texas Health Science Ctr. at Houston (United States)
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Treatment of lymphedema with pneumatic compression device (PCD) therapy is controversial due to the inability to directly measure treatment efficacy. Employing near-infrared (NIR) fluorescence imaging, we evaluated lymphatic function response to PCD therapy in normal, control subjects and unilateral, lymphedema subjects. Lymphatic transport improved in all control subjects and untreated, asymptomatic arms of lymphedema subjects. In the lymphedema subjects, lymphatic transport improved in 4 out of the 6 affected arms. PCDs can stimulate lymphatic function and may be useful for treatment of lymphedema. NIR fluorescence lymphatic imaging may provide direct evidence of therapeutic efficacy.

Near-infrared spectroscopic system and fast inverse Monte Carlo algorithm for endoscopic measurement of tubular tissue

Paper 7896-111 of Conference 7896
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Xiaoqing Zhou, Huijuan Zhao, Zhichao Wang, Feng Gao, Tianjin Univ. (China)
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A near infrared diffuse reflectance spectroscopic system and an inverse algorithm for deriving optical properties are developed. The system works on frequency domain (FD) and a probe was specially designed for endoscopic detection. Measurements for evaluating the accuracy of the system indicate that the deviation in measuring the AC amplitude and phase lag is less than 3.7% and 6.7%, respectively. To eliminate the influence of the initial guess of optical properties on the reconstruction accuracy, an inverse Monte Carlo simulation algorithm with cluster analysis method was developed. Simulation results showed that the relative errors of derivation are less than 6% and those of are less than 10%. Endoscopic measurement on two tubular solid phantoms were also carried out to evaluate the system and the inverse algorithm.

Temporal mapping and connectivity using NIRS for language-related tasks

Paper 7883E-121 of Conference 7883E
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Michael Hall, Ujwal Chaudhary, Florida International Univ. (United States); Gustavo Rey, Miami Children's Hospital (United States); Anuradha Godavarty, Florida International Univ. (United States)
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Near Infrared Spectroscopy (NIRS) offers an invaluable tool to monitor the functionality of the brain. The present study is aimed at using NIRS to understand the functionality of the temporal cortex in response to language-related tasks. A block-design based Word Expression and Word Reception tasks were independently presented to the participants (15 normal subjects) during the imaging study. Herein, the activation, connectivity, and lateralization in the temporal cortex are correlated. In the future, the work is focused to target the pediatric epileptic populations, where understanding the temporal brain functionality in response to language is essential in pre-surgical clinical environment.

Phonon and polaron enhanced IR-THz photodetectors

Paper 7945-34 of Conference 7945
Date: Monday, 24 January 2011
Time: 9:00 AM ?9:20 AM

Author(s): Hui Chun Liu, Chun-Ying Song, Zbigniew R. Wasilewski, Margaret Buchanan, National Research Council Canada (Canada)
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We investigate the active use of phonons and polarons for realizing new optoelectronics devices. We present an application of the concept to photodetection in the infrared-terahertz spectrum. The ability to design a phonon or polaron is the first step in making use of them. We show this by a model system employing the electron intersubband excitation in quantum wells coupled with phonon modes. This results in a photodetector with a high response at the selected wavelength.

Dynamic changes in brain hemodynamics and cerebral metabolic rate of oxygen during repeated squat-stand

Paper 7898-25 of Conference 7898
Date: Monday, 24 January 2011
Time: 9:20 AM ?9:40 AM

Author(s): Haijing Niu, Lin Li, Gauri Suresh Bhave, The Univ. of Texas at Arlington (United States); Rong Zhang, The Univ. of Texas at Dallas (United States); Khosrow Behbehani, Hanli Liu, The Univ. of Texas at Arlington (United States)
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Brain hemodynamics and cerebral metabolic rate of oxygen (CMRO2) can be quantified by a dual-modal brain imager. These quantified parameters may be used as biomarkers to monitor early stage of autoregulation-related diseases, such as Alzheimer's disease (AD) or obstructive sleep apnea (OSA). In this study, we employed both TCD (Trans-cranial Doppler) and DOT (Diffuse Optical Tomography) simultaneously as a combined brain imager so that a mathematical model can be used to accurately quantify CMRO2. A squat-stand protocol was designed during human control group study, and the results have shown significant changes in cerebral hemodynamic parameters and CMRO2 during executing the protocol.

Functional near infrared brain imaging with a brush-fiber optode array to improve study success rates on pediatric subjects with cerebral palsy

Paper 7883G-136 of Conference 7883G
Date: Monday, 24 January 2011
Time: 9:30 AM ?9:50 AM

Author(s): Bilal Khan, The Univ. of Texas at Arlington (United States); Chester Wildey, The Univ. of Texas at Dallas (United States); Fenghua Tian, Mario I. Romero, The Univ. of Texas at Arlington (United States); Mauricio R. Delgado, Nancy J. Clegg, Linsley Smith, Texas Scottish Rite Hospital for Children (United States); Hanli Liu, The Univ. of Texas at Arlington (United States); Duncan L. MacFarlane, The Univ. of Texas at Dallas (United States); George Alexandrakis, The Univ. of Texas at Arlington (United States)
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Neuroimaging techniques are useful to study neuroplastic rearrangements that occur due to dysgenesis, early life injury, or response to treatment in children with cerebral palsy (CP). However, the success rate of radiological imaging studies is low due to motion artifacts. Functional near infrared imaging is robust to motion artifacts but is challenged by scalp-optode optical contact issues. We present novel brush-fiber optodes that overcome scalp contact issues along with computational techniques needed to process such measurements in order to avoid spatial resolution degradation due to larger optode sizes. Validation measurements on children with CP and age-matched controls will be presented.

Optical imaging of signals evoked by infrared neural stimulation of the rat brain.

Paper 7883G-146 of Conference 7883G
Date: Monday, 24 January 2011
Time: 9:50 AM ?10:10 AM

Author(s): Jonathan M. Cayce, Vanderbilt Univ. (United States); Matthew Bouchard, Brenda Chen, Columbia Univ. (United States); E. Duco Jansen, Vanderbilt Univ. (United States); Elizabeth M. C. Hillman, Columbia Univ. (United States); Anita Mahadevan-Jansen, Vanderbilt Univ. (United States)
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Infrared neural stimulation has been well characterized as a novel method to stimulate peripheral nerves without causing damage or inducing a stimulation artifact. To further our understanding of INS induced signals in the brain, multiwavelength optical imaging was used to assess components of the hemodynamic response and calcium dynamics during INS. INS and electrical stimulation was performed in the somatosensory cortex corresponding to the forepaw and hindpaw. INS was performed at 1.875 micron light using repetition rates between 10 - 250 Hz for pulse trains ranging between 500 ms to 1000 ms. The resulting images were compared for signal amplitude, spatial precision, and temporal precision between different laser parameters.

Characterization of infrared neural stimulation in Aplysia californica

Paper 7883G-147 of Conference 7883G
Date: Monday, 24 January 2011
Time: 10:40 AM ?11:00 AM

Author(s): Melanie A. Gault, Austin R. Duke, Vanderbilt Univ. (United States); Hillel J. Chiel, Case Western Reserve Univ. (United States); E. Duco Jansen, Vanderbilt Univ. (United States)
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Infrared neural stimulation (INS) has been shown to induce neural activity with spatial selectivity without inducing a stimulation artifact or necessitating tissue contact. Most experiments with this technology have been done in mammals, but much is still unknown about INS. In this study, INS feasibility in Aplysia is shown and characterized with respect to pulse durations ranging between 2.5-20 ms and repetition rates ranging between 0.5-15 hz. Any statistically significant changes in thresholds among parameter levels are reported. Having shown feasibility in Aplysia, we believe this is a useful model for further studies to unravel the neurobiological mechanisms of INS.

2 W cw OPO in mid-IR pumped by OPSL laser intra-cavity radiation

Paper 7919-9 of Conference 7919
Date: Monday, 24 January 2011
Time: 11:45 AM ?12:00 PM

Author(s): Andrea Caprara, Coherent, Inc. (United States)
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Optically pumped semiconductor lasers (OPSL) are particularly suitable for intra-cavity non-linear frequency generation. Multi-Watt second harmonic, and sub-Watt third harmonic OPSL sources are commercially available in the visible and ultra-violet spectrum. We present work extending the OPSL operation to the mid infra-red by means of an intra-cavity pumped optical parametric oscillator. An output power of 2 Watts at 3.47 microns is reported.

Nerve fiber recruitment in the context of hybrid neural stimulation

Paper 7883G-148 of Conference 7883G
Date: Monday, 24 January 2011
Time: 1:50 PM ?2:10 PM

Author(s): Austin R. Duke, Vanderbilt Univ. (United States); Hui Lu, Michael W. Jenkins, Case Western Reserve Univ. (United States); Melanie A. Gault, Vanderbilt Univ. (United States); Jeff McManus, Hillel J. Chiel, Case Western Reserve Univ. (United States); E. Duco Jansen, Vanderbilt Univ. (United States)
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Recently, hybrid neural stimulation combining electrical and optical techniques was shown to reduce optical stimulation thresholds as much as 3-fold while maintaining spatial selectivity; thus overcoming the risk of thermally-induced tissue damage associated with optical stimulation and the fundamental lack of spatial specificity associated with electrical stimulation. To further develop this technology, we need to better understand the spatial superposition of the electrical and optical stimuli. We will present our investigation of the recruitment of select neurons using infrared neural stimulation and electrical stimulation in the context of developing the hybrid stimulation paradigm.

Silicon membrane photonic crystal microcavities for the mid-infrared

Paper 7946-11 of Conference 7946
Date: Monday, 24 January 2011
Time: 2:30 PM ?2:50 PM

Author(s): Raji Shankar, Irfan Bulu, Marko Loncar, Harvard Univ. (United States)
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We demonstrate the design, fabrication, and experimental characterization of photonic crystal microcavities on a Si membrane platform. L3 photonic crystal cavities with resonances centered around 4.4 祄 were designed using FDTD software, with theoretical quality factors of about 5x103. E-beam lithography and reactive ion etching were used to define the structures in the silicon device layer of a 500-nm thick SOI wafer, and then a HF undercut was performed to produce air bridged photonic crystal cavity structures. Resonant scattering techniques were used to characterize these cavities, with measured quality factors of around 2x103. This represents the first demonstration of mid-infrared photonic crystal cavities in silicon, enabling a wide range of cavity-based on-chip applications, especially in trace gas sensing.

Mid-infrared silicon photonic devices

Paper 7943-25 of Conference 7943
Date: Monday, 24 January 2011
Time: 3:20 PM ?3:50 PM

Author(s): Goran Z. Mashanovich, Milan M. Milosevic, Milos Nedeljkovic, Nathan Owens, William R. Headley, Univ. of Surrey (United Kingdom); Ee Jin Teo, Boqian Xiong, National Univ. of Singapore (Singapore); Pengyuan Yang, Youfang Hu, Univ. of Surrey (United Kingdom)
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The mid-infrared spectral region is interesting for bio-chemical sensing, environmental monitoring, free space communications, or military applications. Silicon is relatively low-loss from 1.2 to 8 祄 and from 24 to 100 祄, and therefore silicon photonic circuits can be used in mid- and far- infrared wavelength ranges. In this paper we investigate several silicon based waveguide structures for mid-infrared wavelength region including silicon-on-insulator rib, ridge and strip waveguides, silicon on porous silicon waveguides, and silicon-on-sapphire waveguides. We also present characterisation of devices based on these waveguides.


Indocyanine green enhanced near-infrared laser treatment of SCK tumors in a mouse model

Paper 7901-37 of Conference 7901
Date: Monday, 24 January 2011
Time: 3:45 PM ?4:00 PM

Author(s): Gal Shafirstein, Univ. of Arkansas for Medical Sciences (United States); Wolfgang Bäumler, Univ. Clinics Regensburg (Germany); Ran Friedman, K. Barnes, Leah Hennings, Jessica Weber, Robert Griffin, Univ. of Arkansas for Medical Sciences (United States)
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The objective of this study was to determine the efficacy of indocyanine green (ICG) dye in enhancing near infrared (NIR) laser ablation of tumors in a mouse model. Tumors were treated with 808-nm laser using 86 J/cm2 radiant exposures preceded by intravenous injection of 4 mg/kg body weight of ICG solution or sterile water. No skin damage was observed in the treated animals. Minor thermal damage and necrosis was observed histologically in the tumor post laser/water treatment and substantial intra-tumor damage was observed in tissue collected from tumors that were treated with laser/ICG.

Wavelength and code-division multiplexing in diffuse optical imaging

Paper 7896-36 of Conference 7896
Date: Monday, 24 January 2011
Time: 4:00 PM ?4:20 PM

Author(s): Luca Ascari, Gianluca Berrettini, Sandro Iannaccone, Scuola Superiore Sant'Anna (Italy); Matteo Giacalone, Consorzio Nazionale Interuniversitario per le Telecomunicazioni (Italy); Davide Contini, Lorenzo Spinelli, Politecnico di Milano (Italy); Maria Giovanna Trivella, Consiglio Nazionale delle Ricerche (Italy); Antonio L'Abbate, Scuola Superiore Sant'Anna (Italy); Luca Potí, Consorzio Nazionale Interuniversitario per le Telecomunicazioni (Italy)
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A novel approach to time resolved diffuse optical imaging, based on the use of wavelength and code division multiplexing is described; this approach, called WS-CDM (wavelength and space code division mltiplexing), promises better performances in terms of signal to noise ratio and acquisition speed, and lower costs compared to both the conventional time-resolved and more recent pseudo-random spread spectrum systems. Parallel acquisition of several wavelengths and from several locations is achievable. Simulations results and preliminary validation on phantom are presented and discussed.

Radio-frequency circuit design and performance evaluation for small animal, frequency domain, NIR fluorescence optical tomography

Paper 7896-37 of Conference 7896
Date: Monday, 24 January 2011
Time: 4:20 PM ?4:40 PM

Author(s): Chinmay D. Darne, Banghe Zhu, Yujie Lu, I-Chih Tan, John C. Rasmussen, Eva M. Sevick-Muraca, The Univ. of Texas Health Science Ctr. at Houston (United States)
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Fluorescence optical tomographic reconstruction from efficient time-dependent measurements involves acquisition measurements through frequency domain photon migration (FDPM) technique. This work focuses on the development and performance evaluation of a rf-circuitry that provides time-dependent information of modulation amplitude and phase shift for tomographic reconstruction. Performance parameters such as its SNR, spatial resolution of measurements, modulation depth (ac/dc) and acquisition time are analyzed prior to incorporation into the gantry of a micro-CT/PET scanner. Incorporation of the rf-circuitry in the CT gantry enables direct quantifiable comparison of the optical tomography values of distribution of dual labeled conjugates using PET imaging as a "gold-standard" measure.

Accurate simulation algorithm of imperfect polarizers combination attenuator

Paper 7941-18 of Conference 7941
Date: Monday, 24 January 2011
Time: 4:40 PM ?5:00 PM

Author(s): Chong Huang, Haiqing Chen, Shuang Zhao, Binbing Liu, Huazhong Univ. of Science and Technology (China)
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The precise attenuation ratio expression of imperfect polarizers combination attenuator (PCA) is proposed based on the Jones Space method. In the infrared target distance simulation in from 2 to 5祄, the analysis of the error in expressing attenuation ratio of the PCA presents that when the angle between the two transmission axes increases to near 90?, the attenuation ratio of this expression is obviously more precise than Malus's Law. Theoretical and experimental results indicate that compared to using traditional expression to calculate the attenuation ratio, simulation algorithm with this expression significantly reduces the simulation error from 50% to 5%.

Attenuation of motion artifact in near infrared spectroscopy signals using a wavelet based method

Paper 7890-21 of Conference 7890
Date: Monday, 24 January 2011
Time: 4:40 PM ?5:00 PM

Author(s): Behnam Molavi, Babak Shadgan M.D., Guy D. Dumont, The Univ. of British Columbia (Canada)
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Sensitivity of Near Infrared Spectroscopy (NIRS) signal to motion artifacts can limit the utilization of NIRS in practical applications. We propose a new wavelet based method for removing movement artifacts from NIRS signals. We tested the method on experimental data collected from leg muscle in 3 patients undergoing leg fracture operation. We compared the performance of our method with that of median and lowpass filtering. The results show an average of 18.32 dB attenuation in motion artifacts energy for our test subjects with the proposed method without introducing significant distortion in artifact-free regions of the signal.

Skeletal muscle oxygenation assessment by near-infrared spectroscopy in intensive care medicine

Paper 7890-22 of Conference 7890
Date: Monday, 24 January 2011
Time: 5:00 PM ?5:20 PM

Author(s): Chun-Yang Wang, National Chiao Tung Univ. (Taiwan); Shinn-Jye Liang, Ming-Lung Chuang, China Medical Univ. Hospital (Taiwan); Ching-Cheng Chuang, National Taiwan Univ. (Taiwan); Yao-Sheng Hsieh, Chia-Wei Sun, National Chiao Tung Univ. (Taiwan)
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In intensive care unit, sepsis and heart failure are the familiar disease of microcirculation. To investigate the disease-induced changes of local metabolic rate and local tissue perfusion adequacy, near-infrared spectroscopy (NIRS) was used for measuring the oxygenation signals on brachioradial muscle during a venous occlusion test (VOT). In this study, the oxygenation signals in ischemic and reperfusion phase via oxygenation response with time-variant pressure VOT (20-50 mmHg) in patients of sepsis, patients of heart failure show obvious different hemodynamics. The oxygenation signal plays an important role to assess the adequacy of oxygen delivery to and oxygen extraction from the microcirculation. Therefore, the measurement can provide a vital sign for clinical diagnosis by quantitative analysis of disease-induced changes from peripheral tissue oxygenation measurement.

Chemical mechanisms and electrical characteristics of C60/Al and C60/LiF/Al cathodes studied by electron spin resonance, infrared reflection-absorption, and impedance spectroscopy

Paper 7935-17 of Conference 7935
Date: Monday, 24 January 2011
Time: 5:10 PM ?5:30 PM

Author(s): Eric D. Glowacki, Johannes Kepler Univ. Linz (Austria) and Univ. of Rochester (United States); Kenneth L. Marshall, Ching W. Tang, Univ. of Rochester (United States); Niyazi S. Sariciftci, Johannes Kepler Univ. Linz (Austria)
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We report our investigations of chemical mechanisms responsible for improved electron injection from LiF|Al cathodes into fullerene thin films. Electron spin resonance (ESR) and infrared reflection-absorption spectroscopy (IRRAS) are utilized to characterize C60|Al and C60|LiF|Al interfaces. ESR shows that deposition of LiF followed by Al generates C60 radical anions with 1-mol% conversion to C60-1, and also an additional paramagnetic species of lower concentration. IRRAS clarifies the mechanism occurring at the interface, showing that interaction between LiF and C60 followed by deposition of Al causes LiF clusters to break apart. We correlate ESR data with observed electrical characteristics.

Effect of 1125-nm laser radiation on porcine skin

Paper 7897-20 of Conference 7897
Date: Monday, 24 January 2011
Time: 5:10 PM ?5:30 PM

Author(s): Kathleen Mcmillan, gRadiant Research, LLC (United States)
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In this work, a new prototype 1125 nm quantum dot diode laser is tested on porcine skin and subcutaneous tissue. Fresh tissue specimens are irradiated and the extent of heating and thermal injury is characterized by temperature monitoring and vital staining. Irradiation times from subsecond to tens of seconds are employed, along with surface cooling at various temperatures. The ability to localize damage at dermal and subcutaneous depths by varying laser parameters is characterized, and compared to the results of mathematical modeling using literature values for optical constants and thermal properties.

An effective method based on reference zone for glucose sensing at 1100-1600 nm

Paper 7906A-17 of Conference 7906A
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Jiaxiang Zheng, Yue Yang, Kexin Xu, Tianjin Univ. (China)
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Non-invasive blood glucose sensing by near-infrared spectroscopy is easily interrupted by the strong background variations compared to the weak glucose signals. In this work, we designed a corresponding optical probe with two detecting zones: a reference zone and a measuring zone. Using the probe, the vitro experiment was conducted in the intralipid solution at 1100-1600nm to build the partial lease-square model. As a result, the corrected model built by two detecting zones has much higher prediction accuracy than the PLS model built by the signal of the measuring zone.

Development of a hand-held 3D photoacoustic imaging system for breast cancer detection

Paper 7899-149 of Conference 7899
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Hazem A. Al-Aabed, Michael B. Roumeliotis, Jeffrey J. Carson, Lawson Health Research Institute (Canada)
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Photoacoustic(PA)imaging is a non-invasive imaging modality that employs non-ionizing near infrared(NIR)laser light to obtain optical images of tissues with depth penetration and resolution comparable to ultrasound imaging. We have constructed a transportable PA imaging system suitable for breast imaging. The system incorporates a hand-held transducer array with 30 detector elements arranged on a ring. It is anticipated that the small hand-held PA imaging unit will be amenable to patient work-up and would complement standard ultrasound imaging.

Discriminant analysis of milk adulteration based on infrared spectroscopy and pattern recognition

Paper 7906A-18 of Conference 7906A
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Rong Liu, Guorong Lv, Bin He, Kexin Xu, Tianjin Univ. (China)
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Since the beginning of the 21st century, the issue of food safety is becoming a global concern. It is very important to develop a rapid, cost-effective, and widely available method for food adulteration detection. In this paper, infrared spectroscopy techniques and pattern recognition were applied to study the qualitative discriminant analysis method.

Infrared spectroscopic imaging of prostate and kidney tumor tissue

Paper 7902-69 of Conference 7902
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Valdas Sablinskas, Vilnius Univ. (Lithuania); Gerald Steiner, Eric Koch, Technische Univ. Dresden (Germany); Justinas Ceponkus, Milda Pucetaite, Simona Strazdaite, Vidita Urboniene, Feliksas Jankevicius, Vilnius Univ. (Lithuania)
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Infrared spectroscopic imaging of cancerous kidney tissue was performed by means of FTIR microscopy. The spectra of thin tissue cryosections were collected with 64x64 MCT FPA detector and imaging area was increased up to 5.4x5.4 mm by mapping by means of PC controlled x,y stage. Chemical images of the samples were constructed using statistical treatment of the raw spectra. Several unsupervised and supervised statistical methods were used. The imaging results are compared with results of the standard histopathological analysis. It was concluded that application of method of cluster analysis ensures the best contrast of the images. It was found that border between cancerous and normal tissues visible in the infrared spectroscopic image corresponds with the border visible in histopathological image. Closer examination of the infrared spectroscopic image reveals that small domains of cancerous cells are found beyond the border in areas distant from the border up to 3 mm.

Transillumination of subcutaneous adipose tissues using near-infrared hyperspectral imaging in the 1100-1800-nm wavelength range

Paper 7902-65 of Conference 7902
Date: Monday, 24 January 2011
Time: 5:30 PM

Author(s): Katsunori Ishii, Akiko Kitayabu, Yohei Kobayashi, Norihiro Honda, Osaka Univ. (Japan); Kunio Awazu, Osaka Univ. (Japan) and Univ. of Fukui (Japan) and Kyoto Univ. (Japan)
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In this study, we constructed the NIR-HSI system and the high-contrast subcutaneous adipose tissue imaging was conducted in-vitro. The NIR super continuum light was delivered to a grating spectrometer and irradiated to the sample. Diffuse reflection light was detected by the InGaAs CCD. In the processed images of characteristic absorption wavelength bands (1200 nm and 1700 nm), subcutaneous adipose tissue was observed through a skin. In a hyperspectral image by another processing using all wavelengths measured by NIR-HSI, a high-contrast image of subcutaneous adipose tissue is also obtained. NIR-HSI system is a powerful diagnostic technique for adipose tissues distribution.

Infrared scanning white light interferometry using a solid state light source

Paper 7928-8 of Conference 7928
Date: Tuesday, 25 January 2011
Time: 8:40 AM ?9:00 AM

Author(s): Ville Heikkinen, Ben Wälchli, Heikki Räikkönen, Juha P. Aaltonen, Ivan Kassamakov, Edward Hæggström, Univ. of Helsinki (Finland)
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Scanning White Light Interferometry (SWLI) allows surface characterization of MEMS components. With transparent samples SWLI can image multiple stacked layer structures. However, since silicon is opaque for visible wavelengths, only the top layer can be measured using visible light. We combined multiple infrared light emitting diodes (IR-LEDs) to achieve adjustable IR illumination. This allows simultaneous measurement of top and bottom surfaces of silicon samples - such as MEMS - using the SWLI equipped with an IR camera. This advances the state of the art of the field of MEMS characterization by allowing measurement of the devices during the operation.

Bioconjugated ICG-micellar nanocapsules as translational fluorescent agents for in-vivo optical molecular imaging

Paper 7910-25 of Conference 7910
Date: Tuesday, 25 January 2011
Time: 9:10 AM ?9:30 AM

Author(s): Yong-Ping Chen, The Johns Hopkins Univ. (United States); Kyle L. Davis, North Carolina State Univ. (United States); Michelle Garner, Tulane Univ. (United States); Xingde Li, The Johns Hopkins Univ. (United States)
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To enable bioconjugation for tumor targeting and molecular imaging, the (PEO)-OH terminals on the corona of the ICG-micelles are pre-activated and then conjugated with antibodies. Recently in vivo fluorescence imaging of tumor-bearing mice with bioconjugated ICG-micelles has demonstrated strong enhancement in molecular specificity when comparing with nonconjugated ICG-micelles or free ICG. The bio-functionalized ICG-nanocapsules hold strong promise for translating optical molecular imaging to in vivo clinical practice.

Multispectral imaging system for imaging O2Hb and HHb concentration changes in tissue for various clinical applications

Paper 7890-26 of Conference 7890
Date: Tuesday, 25 January 2011
Time: 9:20 AM ?9:40 AM

Author(s): John H. Klaessens, Rowland de Roode, Univ. Medical Ctr. Utrecht (Netherlands); Rudolf Verdaasdonk, Vrije Univ. Medical Ctr. (Netherlands); Herke J. Noordmans, Univ. Medical Ctr. Utrecht (Netherlands)
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Non-invasive, non-contact imaging techniques are useful to observe local variations in temperature, oxygenation and blood perfusion over large tissue areas. In this study, three oxygenation imaging methods using either a multi-spectral filter or a tunable LED array light source were evaluated. Narrowband images obtained from controlled in vivo perfusion changes in the skin concentration were used to calculate the changes in hemoglobin concentration (dO2Hb and dHHb). The relative changes in oxygenation and temperature could be clearly observed in good correlation with the physiological condition. The algorithms and data collection/processing can be optimized to enable a real-time diagnostic technique.

Synthesis and characterization of CdHgTe/SiO2 nanoparticles for in-vivo study of their dynamic distribution in mouse model

Paper 7910-26 of Conference 7910
Date: Tuesday, 25 January 2011
Time: 9:30 AM ?9:50 AM

Author(s): Haiyan Chen, Sisi Cui, Yueqing Gu, China Pharmaceutical Univ. (China)
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In this study, CdHgTe/SiO2 core-shell nanoparticles were synthesized by coating of silylating reagent on the surface of CdHgTe QDs. The size change after coating a silica shell had been characterized by laser size analyzer. Photoluminescence studies showed that the silica shell resulted in a minor decline of fluorescence intensity and greatly increased photostability in phosphate-buffered saline buffers. Acute toxicity study indicated the obvious toxicity reduction of CdHgTe QDs after coating with silica shell. The dynamic bio-distribution of CdHgTe/SiO2 nanoparticles in living mouse was in vivo monitored by a NIR imaging system. Results indicated the liver-intestine metabolic pathway of these Nanoparticles.

Assessing dynamic vascular changes in breast tissue in response to subject-specific hyperoxic and hypercarbic gas inhalation based upon end-tidal expiration

Paper 7896-46 of Conference 7896
Date: Tuesday, 25 January 2011
Time: 10:40 AM ?11:00 AM

Author(s): Shudong Jiang, Brian W. Pogue, Michael A. Mastanduno, Kelly E. Michaelsen, Dartmouth College (United States); Tracy E. Frazee, Dartmouth Hitchcock Medical Ctr. (United States); Keith D. Paulsen, Dartmouth College (United States); Steven P. Poplack, Wendy A. Wells, Roberta M. diFlorio-Alexander, Peter A. Kaufman, Dartmouth Hitchcock Medical Ctr. (United States)
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The dynamic vascular changes in the breast due to the prospective targeted and sustained end-tidal pO2 and pCO2 variation were imaged by a fast frame rate frequency domain tomographic system. We obtain information on the variation in dynamic vascular changes as a function of age and breast density and the time dependence of dynamic changes within the breast during hyperoxia, hypercarbia and recovery periods, basing the change upon end-tidal values instead of administered gas values.

Microbolometers for thermography and night vision markets

Paper 7930-11 of Conference 7930
Date: Tuesday, 25 January 2011
Time: 10:40 AM ?11:10 AM

Author(s): Eric Mounier, Yole Développement (France)
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Driven by cost reductions and new commercial applications, new companies from the MEMS business are entering the Uncooled IR market. We have estimated the volumes of camera sold will triple by 2015 and the revenue growth will be about + 9% as market prices for the cameras decrease. MEMS-based microbolometers will be the dominant uncooled IR detector technology with already more than 95 % of the market in 2010. Today, more than 75 % of the production is based in USA, due the original development of the technology by US Defense Department. But this landscape will change in the next five years as many new players (Sensonor, Faun Infrared, Bosch ...), focusing only on selling detectors, often in Europe, will enter on the market place with aggressive price strategies. Microbolometers technical trends will be reviewed as well: Wafer Level Packaging, Pixel Level Packaging, pixel size reduction, 3D integration.

Asymmetric InAs/GaSb superlattice pin photodiode to improve temperature operation

Paper 7945-55 of Conference 7945
Date: Tuesday, 25 January 2011
Time: 11:00 AM ?11:20 AM

Author(s): Philippe Christol, Cyril Cervera, Jean Baptiste Rodriguez, Univ. Montpellier 2 (France); Katarzyna Jaworowicz, Isabelle Ribet-Mohamed, ONERA (France)
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A MWIR asymmetric InAs/GaSb superlattice pin photodiode was fabricated by MBE on p-type GaSb substrate and characterized as a function of temperature. The SL structure was made of 7.5 InAs monolayers (MLs) and 3.5 GaSb MLs, for a total thickness of 1 祄 and exhibits at 80K a cut-off wavelength of 5.5祄. A set of electro-optical characterizations including dark current, spectral response and quantum efficiency were performed on single detectors. As a result, R0A product reaches 1x106?.cm2 at 77K and analysis of dark current characteristics shows that the diode is diffusion limited above 140K and generation-recombination limited below 140K.

Room temperature photovoltaic response of split-off band infrared detectors with a graded barrier

Paper 7945-56 of Conference 7945
Date: Tuesday, 25 January 2011
Time: 11:20 AM ?11:40 AM

Author(s): A. G. Unil Perera, Steven G. Matsik, P. K. Duleepa D. P. Pitigala, Yan-Feng Lao, Georgia State Univ. (United States); Suraj P. Khanna, Lianhe Li, Edmund H. Linfield, Univ. of Leeds (United Kingdom); Zbigniew R. Wasilewski, Margaret Buchanan, Xiaohua Wu, Hui Chun Liu, National Research Council Canada (Canada)
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Dark current reduction in split-off band detectors using photovoltaic operation proposed. A graded barrier is used to produce an asymmetric band structure. Differences in transport probabilities in the two directions lead to the generation of a built-in potential in the device that is used for detection. Preliminary measurements made on a detector with a single graded barrier show a response of ~1.2 mV and a strong current when illuminated with an IR lamp. Possible improvements to increase the response including optimization of the graded barrier and the use of multiple periods will be discussed.

Enhancing the performance of infrared detectors for space applications

Paper 7945-57 of Conference 7945
Date: Tuesday, 25 January 2011
Time: 11:40 AM ?12:00 PM

Author(s): David A. Cardimona, Danhong Huang, Mayor Landau, Chris P. Morath, Brian P. Feller, Air Force Research Lab. (United States)
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At the Air Force Research Laboratory's Space Vehicles Directorate, we are investigating how nanostructured metal surfaces can produce plasmon-enhanced fields to improve detectivity of a detector material placed directly below the metal surface. We are also investigating a wavelength-tunable detector scheme that involves a coupled double quantum well structure, and tunable filters using metamaterials. Not only might these new metamaterials present us a way to tune the light that is incident upon a detector, but such research might also lead to ways to obtain sub-diffraction-limit resolution and the concentration of light using flat lenses for increased signal-to-noise ratios.

Heterogeneous GaSb/SOI mid-infrared photonic integrated circuits for spectroscopic applications

Paper 7945-58 of Conference 7945
Date: Tuesday, 25 January 2011
Time: 1:30 PM ?1:50 PM

Author(s): Nannicha Hattasan, Univ. Gent (Belgium); Laurent Cerutti, Jean-Baptiste Rodriguez, Eric Tournie, Univ. Montpellier 2 (France); Dries Van Thourhout, Günther Roelkens, Univ. Gent (Belgium)
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We report our work on the integration of GaSb-based epitaxy on Silicon-on-insulator (SOI) waveguide circuit based on a die-to-wafer bonding technology with DVS-BCB used as bonding agent. We demonstrate the integration of GaSb-based photodetectors on SOI waveguide circuits (responsivity >0.4A/W). The device is designed based on an evanescent coupling approach, in which light is coupled from the SOI waveguide to the absorbing GaSb-based layer when phase matching occurs. We also show that with our bonding approach, ~150 nm bonding thickness is easily achievable.

Illumination system design for hyperspectral imaging

Paper 7891-27 of Conference 7891
Date: Tuesday, 25 January 2011
Time: 1:50 PM ?2:10 PM

Author(s): Jaka Katra歯ik, Franjo Pernu? Bo歵jan Likar, Univ. of Ljubljana (Slovenia)
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Hyperspectral imaging is becoming a popular tool in the biomedical field. As in all imaging systems, illumination is one of the most important factors affecting the acquired image quality. In hyperspectral imaging the aim is to acquire the spectral signature of all parts of the object. Therefore the whole object must be equally well illuminated - eliminating shadows and specular reflections, while maintaining a high degree of light efficiency. The light illuminating the object must be completely spectrally, spatially and angularly homogeneous. A design that achieves optimal homogeneity of these parameters, while still maintaining a high degree of efficiency is presented.

Strained Layer Superlattice (SLS) single and dual color Focal Plane Arrays (FPAs) at Teledyne Imaging Sensors

Paper 7945-60 of Conference 7945
Date: Tuesday, 25 January 2011
Time: 2:10 PM ?2:30 PM

Author(s): Allan J. Evans, Andrew D. Hood, Paul H. Kobrin, William E. Tennant, Teledyne Imaging Sensors (United States)
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Infrared imaging sensors based on InAs/GaSb Strained Layer Superlattice (SLS) detectors are a very promising, emerging technology that offer the potential of higher temperature operation and design flexibility without the performance tradeoffs found in existing detectors today. This talk will present the most recet results in the development of SLS-based FPAs. Teledyne has recently demonstrated single color, LWIR (~10祄 cutoff at 78K), SLS detectors with high quantum efficiency and dark current that is within a factor of 13 of the best Auger-limited HgCdTe detectors. In addition to single wavelength detectors, Teledyne is currently developing MWIR/LWIR two-color detectors and fabricating both 256x256 and 1kx1k FPAs .



3D tomographic breast imaging using a handheld optical imager

Paper 7896-53 of Conference 7896
Date: Tuesday, 25 January 2011
Time: 2:30 PM ?2:50 PM

Author(s): Sarah Erickson, Sergio Martinez, Jean Gonzalez, Manuela Roman, Annie Nunez, Anuradha Godavarty, Florida International Univ. (United States)
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Hand-held optical imagers are developed toward clinical imaging of breast tissue. However, the optical devices are not able to coregister the image to the tissue geometry for 3D tomography. We have developed a hand-held optical imager which has demonstrated coregistered imaging and 3D tomography in phantoms, and validated coregistered imaging in normal human subjects. Herein, extensive studies are performed to improve the accuracy of coregistered imaging of normal human subjects. Currently 3D tomography analysis is carried out using the coregistered images. The results will demonstrate the potential to perform automated coregistered imaging and feasibility of 3D tomographic imaging in vivo.

Defect density reduction in InAs/GaSb type II superlattice focal plane array infrared detectors

Paper 7945-61 of Conference 7945
Date: Tuesday, 25 January 2011
Time: 2:30 PM ?2:50 PM

Author(s): Martin Walther, Robert H. Rehm, Johannes Schmitz, Jasmin Niemasz, Frank Rutz, Andreas Wörl, Lutz Kirste, Fraunhofer-Institut für Angewandte Festkörperphysik (Germany); Ralf Scheibner, Joachim C. Wendler, Johann Ziegler, AIM Infrarot-Module GmbH (Germany)
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An essential point for the performance of two-dimensional InAs/GaSb short-period superlattices (SL) focal plane infrared detectors is the number of defective pixel. Sources for pixel outages are manifold and might be caused by the dislocation in the substrate, the epitaxial growth process or by imperfections during the focal plane array fabrication process. To examine the crystalline quality of 3'' and 4''GaSb substrates, synchrotron white beam X-ray topography (SWBXRT) was employed. Optical characterization techniques for defect characterization after MBE growth reveal a good correlation of epitaxially grown defects with the detector performance after hybridization with the read-out integrated circuit.

Fabrication and testing of MEMS-based optical filter combined with HgCdTe detector

Paper 7930-19 of Conference 7930
Date: Tuesday, 25 January 2011
Time: 2:50 PM ?3:10 PM

Author(s): Dmitry A. Kozak, Univ. of California, Santa Cruz (United States) and EPIR Technologies, Inc. (United States); Silviu Velicu, EPIR Technologies, Inc. (United States); Joel Kubby, Univ. of California, Santa Cruz (United States)
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We present results for an integrated micro-opto-electro-mechanical device consisting of a Fabry-Perot interferometer with germanium and silicon oxide quarter-wavelength Bragg stack mirrors and a HgCdTe detector suitable for operation in MWIR range. Fabrication methods for the opto-mechanical components are developed, with special emphasis on wafer-scale production. Following discussion of the fabrication of the optical components, we present optical testing of several configurations and correlation to theoretical and simulation results. Stress induced by deposition of optical coatings and its effect on the opto- mechanical behavior of the device is investigated. A process flow for the opto-mechanical component is developed. A device geometry for future integration with HgCdTe and IC layers is discussed.

Near-infrared dipyrrin-based fluorogenic chelators for metal ions

Paper 7910-32 of Conference 7910
Date: Tuesday, 25 January 2011
Time: 3:30 PM ?3:50 PM

Author(s): Sergei A. Vinogradov, Sujatha Thyagarajan, Univ. of Pennsylvania (United States); Brahma Ghosh, Anna V. Moore, Harvard Medical School (United States); Andrei V. Cheprakov, Lomonosov Moscow State Univ. (Russian Federation)
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We report a family of new dipyrrin-based fluorogenic chelators for Zn and other metal ions. The spectral properties of the new family of dipyrrins are tunable over the visible/near infrared range by way of annealing of the pyrrolic residues with external aromatic fragments. The fluorescence of metalldipyrrinates can be switched on and off upon changing the mode of metal coordination. Water-soluble dendritic pi-extended dipyrrins were prepared and evaluated as turn-on fluorescent sensors for Zn2+ showing micromolar binding affinity and bright fluorescence in aqueous solutions.

Ho:YAG laser pumped walk-off compensated mid-infrared ZGP optical parametric oscillation

Paper 7917-21 of Conference 7917
Date: Tuesday, 25 January 2011
Time: 4:00 PM ?4:20 PM

Author(s): Xiaodong Mu, Helmuth E. Meissner, Huai-Chuan Lee, Onyx Optics Inc. (United States)
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We have demonstrated a novel folded linear resonator for walk-off compensated (WOC) optical parametric oscillation (OPO) in a single ZGP crystal. The OPO uses the doubled ZGP crystal length in a WOC configuration meanwhile has simplified requirements on crystal alignment. With a Q-switched Ho:YAG laser as a pump source, a maximum output power of 1.72 W at a wavelength of 4.67 um has been measured at a pump power of 11.7 W in a 15-mm long type-I phase-matched ZGP crystal. The measured OPO quantum slope efficiency is above 50%.

Lateral diffusion of minority carriers in InAsSb-based nBn detectors

Paper 7945-65 of Conference 7945
Date: Tuesday, 25 January 2011
Time: 4:15 PM ?4:30 PM

Author(s): Elena Plis, Stephen Myers, Maya N. Kutty, Julien Mailfert, Ctr. for High Technology Materials (United States); Edward P. Smith, Scott Johnson, Raytheon Vision Systems (United States); Sanjay Krishna, Ctr. for High Technology Materials (United States)
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InAsSb is a good candidate for the development of room temperature MWIR photodetectors. We report on the investigation of lateral diffusion of minority carriers in nBn InAsSb detectors. Diffusion lengths (DL) were extracted from temperature dependent I-V measurements. The behavior of DL as a function of applied bias, temperature, and composition of the barrier layer was investigated. The obtained results suggest that lateral diffusion of minority carriers is not the limiting factor for nBn InAsSb MWIR detector performance at high temperatures (>200K). The detector with AlAs0.1Sb0.9 barrier has demonstrated values of DL as low as 7um (Vb = 0.05V) at 240K.

Development of a mid-infrared tunable optical parametric oscillator pumped by a Q-switched Tm,Ho:YAG laser

Paper 7917-22 of Conference 7917
Date: Tuesday, 25 January 2011
Time: 4:20 PM ?4:40 PM

Author(s): Hisanao Hazama, Osaka Univ. (Japan); Masaki Yumoto, Takayo Ogawa, Satoshi Wada, RIKEN (Japan); Kunio Awazu, Osaka Univ. (Japan)
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Resonant absorption of light due to a variety of different molecular bond with each specific vibration frequency occurs in the mid-infrared (MIR) wavelength region of 5-10 祄. Many medical and biological applications using the selective absorption in the MIR wavelength region have been reported with free electron lasers (FELs) and solid-state lasers using difference-frequency generation (DFG). However, the size and the cost of equipments have been prevented FELs and DFG based solid-state lasers from practical applications. Therefore, we have developed a compact tunable MIR laser using an optical parametric oscillator pumped at a wavelength of 2.1 祄.

Gamma-ray irradiation effects on InAs/GaSb-based nBn IR detector

Paper 7945-66 of Conference 7945
Date: Tuesday, 25 January 2011
Time: 4:30 PM ?4:45 PM

Author(s): Vincent M. Cowan, Christian P. Morath, Seth M. Swift, Air Force Research Lab. (United States); Stephen Myers, Nutan Gautam, Sanjay Krishna, Ctr. for High Technology Materials (United States)
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For space based imaging systems total ionizing dose (TID) radiation hardness continues to be a major performance concern. This paper will present an nBn IR detectors tolerance to TID and proton radiation. The nBn detector under test is composed of an InAs/GaSb SLS absorber (n) and contacts (n) with AlxGa1-xSb barrier (B) grown by solid source molecular beam epitaxy. Both proton induced surface and bulk radiation effects for the nBn IR detector will be characterized in this paper. To the best of our knowledge this is the first time that the TID hardness has been measured for an nBn detector.

Intelligent sensor for color and proximity control in solid state lighting applications

Paper 7954-10 of Conference 7954
Date: Tuesday, 25 January 2011
Time: 4:30 PM ?4:50 PM

Author(s): Alex Gourevitch, Thomas Thurston, Rajiv Singh, Bartosz Banachowicz, Vladimir Korobov, Cliff Drowley, Cypress Semiconductor Corp. (United States)
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We have demonstrated a single-chip light sensor consisting of photo-diode arrays connected to a programmable system-on-chip (PSoC). PSOCs products integrate analog and digital peripheral functions, memory, and a micro-controller. Applications for this light sensor include LED color control in light-mixing applications, and proximity sensing. For color control, the sensor is configured with color filters and the PSOC is programmed to compensate for LED shifts due to temperature, dimming, aging, and binning uncertainty. For proximity sensing, the photo-diode array is configured with a novel near-infrared optical filter that passes wavelengths between 700-1100nm.

Generation of watt level mid-infrared wavelengths using intracavity ZnGeP2 OPO within a 2.1祄 Ho:YAG laser

Paper 7917-23 of Conference 7917
Date: Tuesday, 25 January 2011
Time: 4:40 PM ?5:00 PM

Author(s): Lihao Tan, Nanyang Technological Univ. (Singapore) and DSO National Labs. (Singapore); Poh Boon Phua, DSO National Labs. (Singapore) and Nanyang Technological Univ. (Singapore)
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We would like to report on watt level mid-infrared (MIR) wavelength generation using intracavity ZnGeP_2 (ZGP) optical parametrical oscillator (OPO) within a 2.1祄 Ho:YAG Laser. With the same laser setup, watt level of both 2.1祄 and MIR wavelengths were generated concurrently. An average output power of >10W of 2.1祄 and >1W of MIR wavelength at 5KHz repetition rate were achieved from a 36W Tm Fiber pump laser. Optimizing the output coupling of the Ho:YAG laser achieve 12W of 2.1祄 wavelength. A preliminary result of the intracavity ZGP OPO generates >1W of MIR wavelength.

MRI-guided imaging pulse-oximetry for visualization of breast hemodynamics

Paper 7896-58 of Conference 7896
Date: Tuesday, 25 January 2011
Time: 4:40 PM ?5:00 PM

Author(s): Zhiqiu Li, Shudong Jiang, Venkataramanan Krishnaswamy, Scott C. Davis, Keith D. Paulsen, Brian W. Pogue, Dartmouth College (United States)
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A NIR tomography system with parallel spectral-encoded source arrays at dual-wavelength bands has been built to quantify the temporal NIR contrast available for imaging thick tissues of several centimeters across inside a 3Tesla MRI. The systems were integrated through a customized breast MR coil interface to provide tissue structural information for improved image reconstruction. A MR-compatible pulse oximeter was synchronized to the NIR system to provide heartbeat measurement during imaging. The right breasts of three healthy subjects were imaged and studies were repeated twice on different dates. The periodic variation and time relevance of the absorption coefficients and oxygen saturation in adipose region and fibroglandular region were quantified.

Improvement of mid-infrared pulsed OPOs efficiency by thermal management and cascaded nonlinear conversions

Paper 7917-24 of Conference 7917
Date: Tuesday, 25 January 2011
Time: 5:00 PM ?5:20 PM

Author(s): Antoine Godard, Myriam Raybaut, Thomas Schmid, Michel Lefebvre, ONERA (France); Anne-Marie Michel, Michel Péalat, Sagem Defense Securite (France)
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We report on the theoretical and experiment investigation of thermal effects in pulsed nanosecond OPOs. Based on our investigations, we developed two-zone temperature controlled ovens. With proper adjustments of the applied temperature gradient, we have demonstrated that a significant improvement (more than 30 %) of the conversion efficiency of mid-IR PPLN OPOs can be obtained. We also implemented devices where the resonant signal wave is recycled to pump cascaded nonlinear processes. Such an approach enables us to overcome the photon conversion efficiency imposed by the Manley-Rowe relations, leading to a two-fold improvement of the conversion efficiency toward the mid-IR.

No effect of femtosecond laser pulses on DNA, protein, M13, or E. coli

Paper 7897-41 of Conference 7897
Date: Tuesday, 25 January 2011
Time: 5:00 PM ?5:20 PM

Author(s): Jeffrey C. Wigle, Eric A. Holwitt, Katharine E. Sheldon, U.S. Air Force (United States); Larry E. Estlack, Conceptual MindWorks, Inc. (United States); Gary D. Noojin, TASC, Inc. (United States); Benjamin A. Rockwell, U.S. Air Force (United States)
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We were unable to reproduce published inactivation results, or show any interaction, between 90 femtosecond (fs) pulses of 850 nm or 425 nm laser radiation and buffer/water, DNA, protein, M13 bacteriophage or E. coli. We examined purified plasmid DNA (pUC19), bovine serum albumin, M13 viability, and DNA and coat proteins extracted from M13 at irradiances of up to 120 MW/cm2. Exposures of up 1 GW/cm2 at 850 nm had no effect on the viability of E. coli. Peroxynitrite, known to be toxic, to cause single strand breaks in DNA, and fragment proteins in vitro gave positive results in all assays.

Storable near-infrared chemilumilescent probes for in-vivo optical imaging

Paper 7910-36 of Conference 7910
Date: Tuesday, 25 January 2011
Time: 5:20 PM ?5:40 PM

Author(s): Bradley D. Smith, Univ. of Notre Dame (United States)
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A new class of chemiluminescent and fluorescent dyes and dye-doped nanoparticles can be stored at zero degrees and then made to emit near-infrared light by warming to body temperature (no chemical or electrical stimulus is needed). In vivo chemiluminescence imaging permits identification of target sites that are five times deeper than planar fluorescence imaging. A new imaging paradigm employs the dual modality probes first in high contrast chemiluminescence mode to locate relatively deep anatomical locations in vivo and subsequently in fluorescent mode to identify the microscopic targets within thin histopathology sections taken from the same specimen.

Infrared metamaterial design using derivative-free numerical optimization

Paper 7946-31 of Conference 7946
Date: Tuesday, 25 January 2011
Time: 5:40 PM ?6:00 PM

Author(s): Kenneth Diest, Luke A. Sweatlock, Daniel E. Marthaler, Northrop Grumman Aerospace Systems (United States)
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In this work, we characterize optical metamaterials with full-field electromagnetic simulations and convert the output to scalar valued objective functions. Evolution of the device design is then cast as a minimization problem in parameter space, which we address using a derivative-free, nonlinear mesh adaptive search technique. We apply this numerical optimization method, in combination with full-field electromagnetic simulations, to design split-ring resonator "notch filters", with narrow pass bands across the near to mid infrared spectrum. The tunability of the corresponding line width at the pass band and percent change in reflectivity are analyzed and compared with traditional parameter sweeps.

Non-destructive analysis on femtosecond laser doped silicon

Paper 7920-44 of Conference 7920
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Yu-Ting Lin, Harvard Univ. (United States); Matthew J. Smith, Silvija Gradecak, Massachusetts Institute of Technology (United States); Eric D. Mazur, Harvard Univ. (United States)
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Silicon doped with Chalcogens using femtosecond laser pulses can achieve a high doping concentration (~1 %) and unique properties. This material exhibits near-unity absorption extending from the visible to the mid-infrared and metallic-like conduction. Thus, it is a potential candidate for advanced optoelectronic devices. To further understand this material, we utilize non-destructive optical tools including Raman spectroscopy and FTIR to characterize laser-induced changes in crystallinity, dopant profiles, and optical properties at various processing parameters. Our findings contribute to a better understanding of the structural and optical characteristics, completing a picture of the silicon surface condition after femtosecond laser irradiation.

The research of the laser facula of laser ranger finder in the far distance

Paper 7912-71 of Conference 7912
Date: Tuesday, 25 January 2011
Time: 6:00 PM

Author(s): Rongguo Fu, Nanjing Univ. of Science & Technology (China)
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The lateral intensity of the facula of a beam of 1.06祄 laser pulse light of a laser range findeis not an ideal Gauss distribution. A testing device is designed to measure the facula of the laser light in the far distance. The device has a near infrared CCD camera, a filter of 1.06祄 is applied. Another white light CCD is applied to obtain the background. A lens is designed for both cameras. The near infrared CCD is synchronous with laser ranger finder, The image of the facula is analyzed, the intensity distribution of the facula is obtained.

Optical biopsy of the prostate: can we TRUST (trans-rectal ultrasound-coupled spectral tomography)?

Paper 7895-18 of Conference 7895
Date: Wednesday, 26 January 2011
Time: 8:00 AM ?8:30 AM

Author(s): Daqing Piao, Jiang Zhen, Kenneth E. Bartels, G. Reed Holyoak, Jerry W. Ritchey, Charlotte L. Ownby, Kendra Rock, Charles F. Bunting, Oklahoma State Univ. (United States); Gennady Slobodov, The Univ. of Oklahoma Health Sciences Ctr. (United States)
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The trans-rectal ultrasound-coupled spectral tomography (TRUST) approach has evolved and been evaluated on one normal canine prostate and three dogs with implanted prostate tumor developed as a model. TRUST has demonstrated potentials in the following diagnostic outcome: (1) finding the onset of prostate tumor earlier than by using ultrasonography alone; (2) quantifying changes of blood concentration and the indicated mass-volume of a rapidly growing prostate tumor; (3) differentiating different characteristics of tumor and cystic lesion; and (4) indicating tumor metastasis to inguinal or pelvic lymph nodes. Intensive technologic development is necessary for translating the approach to clinical practice.

Free-form micromachining of an infrared Alvarez lens

Paper 7927-20 of Conference 7927
Date: Wednesday, 26 January 2011
Time: 8:30 AM ?8:50 AM

Author(s): Paul J. Smilie, Brian Dutterer, Jennifer L. Lineberger, Matthew A. Davies, Thomas J. Suleski, The Univ. of North Carolina at Charlotte (United States)
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In 1967, Luis Alvarez introduced a novel concept for focusing whereby two transmitting plates with cubic polynomial surfaces with small relative lateral shifts yield a composite lens of variable focal length. To date, however, fabricating refractive cubic surfaces of the types needed with adequate precision and depth modulation has proven to be challenging using standard methods. Recent developments in free-form diamond machining capability have enabled the fabrication of such devices. In this paper, we discuss the fabrication of cubic refractive Alvarez plates in infrared materials using diamond micromilling. Machining approaches are presented, and initial results are discussed.

Vertical transport in InAs/GaSb superlattices: model results and relation to in-plane transport

Paper 7945-68 of Conference 7945
Date: Wednesday, 26 January 2011
Time: 8:30 AM ?8:45 AM

Author(s): Frank Szmulowicz, Univ. of Dayton Research Institute (United States); Gail J. Brown, Air Force Research Lab. (United States)
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Operation of InAs/GaSb superlattice-based devices requires efficient transport of carriers perpendicular to superlattice layers by drift and/or diffusion. Vertical transport measurements are difficult and nonstandard, hence we model both the horizontal and vertical electron transport in InAs/GaSb superlattices qua superlattices by solving the Boltzmann equations in the relaxation time approximation, using the interface roughness scattering as the dominant mobility-limiting mechanism. We calculate vertical and horizontal mobilities as a function superlattice parameters such as layer widths, the correlation length of interface roughness, and the Fermi energy. The calculations can be used to estimate vertical mobilities from measurements of horizontal mobilities.

Barrier engineered superlattice and quantum dot detectors for HOT operation

Paper 7945-69 of Conference 7945
Date: Wednesday, 26 January 2011
Time: 8:45 AM ?9:05 AM

Author(s): Jiayi Shao, Thomas E. Vandervelde, Ajit V. Barve, Woo-Yong Jang, Andreas Stintz, Sanjay Krishna, Ctr. for High Technology Materials, Univ. of New Mexico (United States)
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There is an increased emphasis on obtaining higher operating temperature (HOT) detectors as a part of the third generation detector development. In particular, there have been a lot of research efforts in engineering the barriers for reducing the dark current in the infrared detectors. We have been undertaking research on infrared detectors based on InAs/GaAs quantum dots in a well (DWELL) and InAs/GaSb superlattices. We will discuss approaches to incorporate unipolar barriers in the superlattices to prevent noise generating mechanisms. Using barrier engineering, we will show how the operating transition of the dots in a well detector can be engineered to produce higher signal to noise ratios.

Modified type-II superlattices for long wavelength infrared applications

Paper 7945-71 of Conference 7945
Date: Wednesday, 26 January 2011
Time: 9:25 AM ?9:40 AM

Author(s): Yiqiao Chen, SVT Associates, Inc. (United States)
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Here we report a new modification on SL structure that substantially improves the overall performance of type-II InAs/GaSb SL photo detectors including extended cutoff wavelength and improved specific detectivity. In our modified SL design, a thicker InSb layer was used to extend the cutoff wavelength and a thin compressively-strained wider bandgap layer was inserted to balance the strain of the thicker InSb layer. The presence of 2MLs of the wider bandgap material which differs from the more common AlSb variety will help to reduce dark current and sidewall leakage as it serves as a barrier for both electrons and holes in SLs.

Quantitative analysis of formation and thermal stability of oxide phases between SiO2 and InSb

Paper 7945-73 of Conference 7945
Date: Wednesday, 26 January 2011
Time: 9:55 AM ?10:10 AM

Author(s): Jaeyel Lee, Sehun Park, Jungsub Kim, Changjae Yang, Sujin Kim, Chulkyun Seok, Jinsub Park, Euijoon Yoon, Seoul National Univ. (Korea, Republic of)
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In this study, we report the quantitative analysis of indium and antimony oxide at SiO2/InSb interface formed at various growth temperatures during plasma enhanced chemical vapor deposition and subsequent heat treatments. 30 nm-thick SiO2 layers were deposited on InSb at 120, 160, 200, 240 and 300 oC, and analyzed by X-ray photoelectron spectroscopy (XPS). With increasing deposition temperature, contents of indium and antimony oxides were also increased due to the enhanced diffusion. In addition, the sample deposited at 120 oC was annealed at 300 oC for 10 and 30 min and the contents of interfacial oxides were analyzed. Thermodynamic stability and the resulting interfacial solid-state reactions and its effect on the interfacial states will be discussed in detail.

Quantum cascade detectors based on III-nitride heterostructures

Paper 7939-48 of Conference 7939
Date: Wednesday, 26 January 2011
Time: 10:30 AM ?11:00 AM

Author(s): Eva Monroy, Yulia Kotsar, Qiran Li, Prem Kumar Kandaswamy, Commissariat à l'Énergie Atomique (France); Salam Sakr, Maria Tchernycheva, François Julien, Univ. Paris-Sud 11 (France); Alon Vardi, Gad Bahir, Technion-Israel Institute of Technology (Israel)
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Quantum Cascade Detectors (QCDs) are tailorable infrared photodetectors based on intersubband transitions in semiconductor QWs. The device active region comprises multiple periods of active QWs and extractor regions. The extractor is a superlattice structure designed to form a phonon ladder (energy spacing equal to the LO-phonon energy) which collects the electrons in the excited state of the first active QW and injects them in the ground state of the next active QW. In contrast with standard QW infrared photodetectors, QCDs do not require an external bias voltage due to their asymmetric band profile. The operation spectral range of these devices, first demonstrated in the mid-infrared, can be extended to the near-infrared thanks to the large band offsets of III-nitrides. In this work, we summarize the design, growth, fabrication and performance of nitride-based QCDs operating in the 1.4-2.5 祄 spectral range.

Imaging sub-nanomolar concentrations through more than five centimeters of tissue with time-domain diffuse fluorescence tomography

Paper 7896-66 of Conference 7896
Date: Wednesday, 26 January 2011
Time: 10:40 AM ?11:00 AM

Author(s): Frederic Leblond, Fadi El-Ghussein, Brian W. Pogue, Dartmouth College (United States); Kenneth M. Tichauer, Dartmouth College (Canada); Robert W. Holt, Dartmouth College (United States)
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Photodetection based on time-correlated single-photon counting technology is used to demonstrate that diffuse fluorescence tomography can detect fluorophores in transmission through more than five centimeters in tissue-simulating phantoms, and that this can be achieved for sub-nanomolar concentrations with dyes commonly used for in vivo pre-clinical biological studies. Our results demonstrate that an unprecedented level of sensitivity can be achieved with time-domain fluorescence tomography allowing this technology to be used for applications involving animals larger than mice as well as applications where limited contrast is available.


Pixelated resonant subwavelength grating filters for greenhouse gas monitoring

Paper 7941-41 of Conference 7941
Date: Wednesday, 26 January 2011
Time: 11:30 AM ?11:50 AM

Author(s): David W. Peters, Shanalyn A. Kemme, Alvaro A. Cruz-Cabrera, Robert R. Boye, Chad A. Bustard, Sandia National Labs. (United States)
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We describe the design of two pixelated filter arrays for hyperspectral monitoring of CO2 and H2O absorption in the midwave infrared (centered at 4.25 and 5.15microns, respectively) using resonant subwavelength gratings (RSGs), also called guided-mode resonant filters (GMRFs). For each gas, a filter array is made for the absorption band on a single substrate. A pixelated geometry allows for direct registration of filter pixels to FPA sensor pixels and for non-scanning data collection. The design process for narrowband, low-sideband filters within fabrication limitations will be discussed.

Experimental characterization of afterpulsing and timing jitter of InGaAs/InP SPAD

Paper 7934-21 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 11:40 AM ?12:00 PM

Author(s): Fabio Acerbi, Alberto Tosi, Alberto Dalla Mora, Michele Anti, Franco Zappa, Politecnico di Milano (Italy)
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We present the characterization results on afterpulsing and timing jitter of a new generation of InGaAs/InP Single-Photon Avalanche Diodes (SPADs). We first investigate afterpulsing probability, main contributor to detector noise, at different temperatures and excess biases, in order to study their effects on the de-trapping probability. Moreover, we biased the detector with different electric fields during de-trapping time interval in order to study how to enhance trap release. Finally, we performed simulations to cross-check experimental results. We then characterized in depth the timing jitter by changing incident light wavelength, operating temperature, excess bias, and light absorption position.

Advances in the development of type-I quantum well GaSb-based diode lasers

Paper 7953-37 of Conference 7953
Date: Wednesday, 26 January 2011
Time: 1:50 PM ?2:20 PM

Author(s): Gregory Belenky, Leon Shterengas, Stony Brook Univ. (United States); Gela Kipshidze, Stony Brook Univ. (United States) and Power Photonic Corp. (United States); Takashi Hosoda, Jianfeng Chen, Stony Brook Univ. (United States)
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Diode lasers grown on GaSb substrates operate at room temperature in wide spectral region from below 2 祄 to 3.5 祄. We will report on the recent development of the high power 2 祄 diode lasers with improved beam properties and power conversion efficiencies. The results of characterization of the 3 - 3.5 祄 emitting lasers operating in CW regime up to 50 0C and generating hundreds of mW of output power will be presented. We will discuss the development of the single spatial and spectral mode 2 - 3.4 祄 mid-infrared diode lasers with output power in excess of 50 mW. The roadmap to improve the performance parameters of GaSb-based 2.5 - 3.5 祄 emitting diode lasers by using growth on virtual GaInSb substrates will be presented. The experimental results for high power CW room temperature operated diode lasers grown on virtual substrates with lattice constant larger than that of GaSb will be discussed.

High-power continuous-wave interband cascade lasers

Paper 7953-38 of Conference 7953
Date: Wednesday, 26 January 2011
Time: 2:20 PM ?2:40 PM

Author(s): William W. Bewley, Chadwick L. Canedy, Chul Soo Kim, Mijin Kim, J. Ryan Lindle, Joshua Abell, Igor Vurgaftman, Jerry R. Meyer, U.S. Naval Research Lab. (United States)
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Narrow-ridge interband cascade lasers do not show significant degradation of the threshold and efficiency for ridge widths >5.1 祄. The 11.1 and 13.0-祄-wide uncoated ridges produced up to 45 mW/facet of cw power at 20ºC, and displayed maximum wall-plug efficiencies of 3.5% per facet. The 5.1 祄 x 3 mm ridge without any facet coatings operated cw to a new record of 345 K. At T = -23ºC, a distributed-feedback device with 4th-order gratings etched into both sidewalls generates up to 30 mW of single-mode cw power near the strong methane absorption line at ? 3.315 祄.

Respiratory challenges to detect cyanide toxicity extent in a sublethal rabbit model

Paper 7896-73 of Conference 7896
Date: Wednesday, 26 January 2011
Time: 2:30 PM ?2:50 PM

Author(s): Jae Gwan Kim, Jangwoen Lee, Sari B. Mahon, David S. Mukai, Beckman Laser Institute and Medical Clinic (United States); William C. Blackledge, Univ. of California, San Diego (United States); Steven Patterson, Univ. of Minnesota, Twin Cities (United States); Gerry R. Boss, Univ. of California, San Diego (United States); Bruce J. Tromberg, Beckman Laser Institute and Medical Clinic (United States); Matthew Brenner, Univ. of California, Irvine (United States)
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In this study, we tested our hypothesis that the amplitudes of oxy-, deoxyhemoglobin concentration changes during a respiratory challenge from 100% to 21% oxygen will be smaller as cyanide toxicity increases since more oxygen will become available in blood by cyanide poisoning. The results showed that the amplitudes of both oxy-, deoxyhemoglobin concentration changes decreased during cyanide infusion and returned to the baseline level at the end of recovery. These results prove our hypothesis and show that near infrared spectroscopy combined with a respiratory challenge can be a useful non invasive tool for estimating cyanide toxicity extent in vivo.

Implanted near-infrared spectroscopy for cardiac monitoring

Paper 7896-74 of Conference 7896
Date: Wednesday, 26 January 2011
Time: 2:50 PM ?3:10 PM

Author(s): Sourav K. Bhunia, Can Cinbis, Medtronic, Inc. (United States)
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Implanted near-infrared spectroscopy (iNIRS) may augment arrhythmia detection in implanted cardioverter defibrillators by monitoring skeletal muscle perfusion. A two-wavelength iNIRS has been evaluated in-vivo. A weighted difference of the changes in attenuation at two wavelengths was taken to be the microvascular oxygenation trend indicator (O2 Index). The hypothesis that a constant weight may be adequate for hemodynamic trending during short arrhythmic episodes was evaluated. The slope of the O2 Index over 10 seconds was significantly different during normal sinus rhythm and induced ventricular fibrillation in both the fresh and scar tissue pockets. Therefore iNIRS may be useful for hemodynamic monitoring.

High average power short wavelength InGaAs/AlAs(Sb)/InP quantum cascade lasers

Paper 7953-41 of Conference 7953
Date: Wednesday, 26 January 2011
Time: 4:00 PM ?4:30 PM

Author(s): Dmitry G. Revin, Kenneth Kennedy, Shiyong Y. Zhang, Paul Commin, Andrey B. Krysa, John W. Cockburn, The Univ. of Sheffield (United Kingdom)
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We review the development of short wavelength (3 祄 < ? < 3.8 祄) quantum cascade lasers (QCLs) based on the deep quantum well, strain compensated InGaAs/AlAs(Sb)/InP materials system towards continuous wave operation. Investigation of QCLs with various doping levels and improved designs has led to the reduction of the pulsed threshold current and the increase of the characteristic temperatures. Introduction of advanced processing steps has resulted in the short wavelength lasers operating at low temperatures at high duty cycle (up to 50%) and emitting high average output power (several hundreds of milliwatts).

Towards rare-earth-doped chalcogenide glass fibre lasers for the mid-infrared (IR)

Paper 7912-52 of Conference 7912
Date: Wednesday, 26 January 2011
Time: 4:00 PM ?4:20 PM

Author(s): Angela B. Seddon, Zhuoqi Tang, David Furniss, Slawomir Sujecki, Trevor M. Benson, The Univ. of Nottingham (United Kingdom)
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Mid-IR fibre laser operation up to 3 祄 has been demonstrated in fluoride glass fibre. For longer wavelength mid-IR operation, lower phonon energy glass hosts are required. Chalcogenide host glasses offer favourable properties with low phonon energies, down to 350 cm-1, for low non-radiative decay rates, good solubility of rare-earth (RE) ions and high refractive indices leading to high absorption and emission cross-sections. Additionally, Se glass fibres are mechanically robust and chemically durable both in water and in the open atmosphere. We shall report on progress in developing RE-doped selenide glasses to deliver tuneable, monochromatic light beyond 3 祄.

Hierarchical segmentation for improved image reconstruction in diffuse optical tomography of human prostate cancer

Paper 7896-77 of Conference 7896
Date: Wednesday, 26 January 2011
Time: 4:20 PM ?4:40 PM

Author(s): Venkaiah C. Kavuri, Zi-Jing Lin, Hanli Liu, The Univ. of Texas at Arlington (United States)
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The inclusion of anatomical prior information in reconstruction algorithms can improve the quality of reconstructed images in near infrared diffuse optical tomography (DOT). The prior information on possible locations of human prostate cancer from trans-rectal ultrasound (TRUS) is very limited and could be false negative, which may lead to biased reconstructed images. The prior information can be obtained by simultaneous measurements or individual measurements from two or more modalities. But in case of TRUS-coupled, DOT probe, the inverse problem could be worse due to a limited number of measurements. Motivated by these shortcomings, we have focused in our study on (1) the development of a hierarchical segmentation approach to improve the reconstruction algorithm for DOT and (2) to compare the reconstructed optical properties using a TRUS-NIR-combined probe and NIR-standalone probe. With computer simulations, we generated a mesh which resembled the rectum and had the anomaly at 2-cm depth below the rectum. The optodes were placed on the surface of the rectal wall, resembling the probe array touching the rectal wall. Furthermore, the experimental data were taken using a DOT probe array, similar to that used in the numerical simulation. A laboratory phantom was made of gelatin-intralipid for the laboratory experiments with two different probe geometries (rows x columns: 8x2, 6x3 for TRUS-NIR, NIR standalone), respectively. A continuous wave system was used in both simulations and experiments to determine the optical properties. Reconstructed images from both probe configurations demonstrate that hierarchical segmentation is an effective means to improve image reconstruction in DOT.

Optical properties and applications of liquid crystals in the THz frequency range

Paper 7955-25 of Conference 7955
Date: Wednesday, 26 January 2011
Time: 4:30 PM ?5:00 PM

Author(s): Ci-Ling Pan, National Tsing Hua Univ. (Taiwan)
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In the past decade, THz studies ranging from investigations of ultrafast dynamics in materials to medical, environmental sensing and imaging have been actively explored. For these and future applications in THz communication and surveillance, quasi-optic components such as phase shifters are indispensable. The birefringence of liquid crystal (LC) is well known and extensively utilized for the manipulation of optical radiation in the visible and near-infrared range. Recently, there have been increasing interests in the study of liquid-crystal-based devices for application in the sub-millimeter wave or THz frequency range. In this paper, we review recent available optical constants of selected liquid crystals in this important frequency range and recent advances in liquid crystal THz optic and photonic devices.

A simple model for 2-D image up-conversion of incoherent light

Paper 7917-39 of Conference 7917
Date: Wednesday, 26 January 2011
Time: 5:10 PM ?5:30 PM

Author(s): Jeppe S. Dam, Christian Pedersen, Peter Tidemand-Lichtenberg, Technical Univ. of Denmark (Denmark)
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We present a simple model and experimental data for 2 dimensional image up-conversion of incoherent light. The model predicts the feasibility of a mid-infrared camera based on conventional silicon CCD technology combined with a wavelength converter module. While the principle has been known for more than 40 years, the practical applicability of the technology has been hindered by very low conversion quantum efficiency (~10-7). We show that our technological and conceptual improvements promise a conversion quantum efficiency in the order of 10-2. We believe that the presented technology opens up new possibilities for sub microsecond thermal imaging of hot events, as well as potentially low cost image acquisition devices in the mid- and far-infrared spectral range.

Mode-locking of a Cr:ZnSe laser by use of a PPLN nonlinear mirror

Paper 7912-56 of Conference 7912
Date: Wednesday, 26 January 2011
Time: 5:20 PM ?5:40 PM

Author(s): Jean-Baptiste Dherbecourt, Antoine Godard, Adrien Denoeud, Jean-Michel Melkonian, Myriam Raybaut, Michel Lefebvre, Emmanuel Rosencher, ONERA (France)
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We report on the first experimental demonstration of the passive mode-locking of a Cr:ZnSe laser by a tunable PPLN-based nonlinear mirror. The Cr:ZnSe (lambda 2.5 祄) laser is pumped by a CW thulium-doped fiber laser. An intracavity second-harmonic generator based on a PPLN crystal coupled with a dichroïc mirror (highly reflective at the second harmonic and partially reflective at the fundamental wave) and a dispersive YAG wedged plate is used as an amplitude modulator to achieve mode-locked operation. During this presentation we will discuss the role played by each nonlinear mirror component and their influence on the laser's dynamics.

Thermal investigation of mid-infrared quantum cascade lasers under quasi-continuous-wave operations

Paper 7953-70 of Conference 7953
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Xing Chen, Liwei Cheng, Dingkai Guo, Fow-Sen Choa, Terrance Worchesky, Univ. of Maryland, Baltimore County (United States)
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The temperature effect on the characteristics of strain-balanced mid-infrared quantum cascade lasers (QCL) is theoretically investigated and compared to experimental results. Our theoretical model simulates the temperature dependence of modal gain, current threshold density, and optical output power of a QCL at pulsed, continuous wave (CW), and quasi-CW operation conditions. Simulation results show that QCLs operated at quasi-CW driving condition expresses much lower laser core temperature than CW mode while generates comparable or even higher average power than CW mode. The model can be used to predict the optimum driving condition in order to generate maximum average output power.

Toward single-material multilayer interference mid-infrared filters with sub-wavelength structures for cryogenic infrared astronomical missions

Paper 7934-47 of Conference 7934
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Hironobu Makitsubo, Japan Aerospace Exploration Agency (Japan) and The Univ. of Tokyo (Japan); Takehiko Wada, Makoto Mita, Japan Aerospace Exploration Agency (Japan)
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We are developing high performance mid-infrared multilayer interference filters with mechanical strength and robustness for thermal cycling toward cryogenic infrared astronomical missions. To realize these filters, we introduce sub-wavelength structures (SWS) for controlling the refractive index and plan to fabricate filters with only one material. To verify the controllability of refractive index by such simple SWS, periodic cylindrical holes on a bulk material, we have fabricated SWS on a silicon substrate. Comparing measured transmittance with theoretical transmittance calculated by effective medium approximation theory and RCWA simulation, we confirm that we can control the refractive index of SWS by changing porosity.

A surface plasmon enhanced infrared photo-detector based on InAs quantum dots

Paper 7946-53 of Conference 7946
Date: Thursday, 27 January 2011
Time: 9:30 AM ?10:00 AM

Author(s): Shawn-Yu Lin, Rensselaer Polytechnic Institute (United States)
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In this talk, I will demonstrate a successful realization and integration of a gold two-dimensional-hole-array (2DHA) with InAs quantum-dot (QD). I will show that a properly designed 2DHA-QD photodetector can facilitate a strong plasmonic-QD interaction, leading to a 130% absolute enhancement of infrared photo-response at the plasmonic resonance.

Optical cooling in Nd-doped crystals and nanocrystalline powders revisited

Paper 7951-5 of Conference 7951
Date: Thursday, 27 January 2011
Time: 9:40 AM ?10:10 AM

Author(s): Angel J. Garcia-Adeva, Rolindes Balda, Mohammed Al Saleh, Sara Garcia-Revilla, Joaquin Fernandez, Univ. del País Vasco (Spain)
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In the present work, we report on infrared thermography measurements in Nd-doped KPb2Cl5 crystal and powder above and below the barycentre of the 4F3/2 level that were performed in order to assess the relative weights of both the direct anti-Stokes absorption processes and those assisted by either excited state absorption or energy transfer upconversion processes in the cooling of the material. As the laser induced temperature changes are usually small, we used a special configuration of the samples that allowed us to obtain diferential measurements where an undoped sample acted as a temperature baseline. This method allows us to ascertain whether the recorded temperture changes are optically induced or they are due to some other effect.

Compact detection module based on InGaAs/InP SPADs for near-infrared single-photon counting up to 1.7 祄

Paper 7945-95 of Conference 7945
Date: Thursday, 27 January 2011
Time: 10:30 AM ?10:50 AM

Author(s): Alberto Tosi, Andrea Bahgat Shehata, Politecnico di Milano (Italy); Adriano Della Frera, Micro Photon Devices S.r.l. (Italy); Alberto Dalla Mora, Politecnico di Milano (Italy); Simone Tisa, Micro Photon Devices S.r.l. (Italy); Fabio Acerbi, Franco Zappa, Politecnico di Milano (Italy)
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Nowadays, InGaAs/InP Single-Photon Avalanche Diodes (SPADs) have good enough performance to be successfully employed in many applications that demand to detect single photons in the 1 - 1.7 祄 wavelength range. However, in order to fully exploit such InGaAs/InP SPADs, it is mandatory to operate them in optimized working conditions by means of dedicated electronics. We present the design and experimental characterization of a high-performance compact detection module able to operate at best InGaAs/InP SPADs. It can be easily tailored for different specific applications and proves state-of-the-art performance.

Optical frequency conductance model of teraHertz/infrared emission and detection in quantum wells, quantum dots, and narrow-gap semiconductors

Paper 7938-9 of Conference 7938
Date: Thursday, 27 January 2011
Time: 11:40 AM ?12:00 PM

Author(s): Thomas Szkopek, Elizabeth Ledwosinska, McGill Univ. (Canada)
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The optical frequency conductance is derived for quantum wells and quantum dots, and the optical frequency conductivity of bulk narrow-gap semiconductors is revisited. The teraHertz (THz) and infrared (IR) response of these structures, in free-space and guided-wave geometries, is simply described within the optical frequency conductance formalism. The fine structure constant of quantum electrodynamics sets the natural scale for the optical conductance of semiconductor structures. Rules of thumb and physical limits to THz/IR gain and absorption can be derived. The optical conductance formalism is applied to MCT photodetectors, quantum well IR photodetectors, quantum dot IR photodetectors, and quantum cascade lasers.

Optical wireless networked-systems: applications to aircrafts

Paper 7958-18 of Conference 7958
Date: Thursday, 27 January 2011
Time: 11:40 AM ?12:10 PM

Author(s): Mohsen Kavehrad, Jarir Fadlullah, The Pennsylvania State Univ. (United States)
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Progress in semiconductor technologies facilitates production of efficient light-based in-flight entertainment, distributed sensing and navigation systems. Investigation of energy-efficient, transceivers will create a wireless medium, providing enhanced security, and improved performance for communications in greater harmony with onboard systems. Applications seamlessly inter-connect multiple devices in a network that is deployable for several aircrafts onboard systems. Recent experimental results on a high-capacity infrared system are presented. A laser source can be applied in a hybrid package along with a visible lighting LED for both lighting and communications. Also, we present a combination of light communications through "Spotlighting" and existing onboard power-lines. It is demonstrated that a high-capacity visible light system communicating over existing power-lines may lead to savings in many areas through reduction of size, weight and power consumption.

Future directions in quasi-phasematched semiconductors for mid-infrared lasers

Paper 7917-50 of Conference 7917
Date: Thursday, 27 January 2011
Time: 1:15 PM ?1:35 PM

Author(s): Peter G. Schunemann, Scott D. Setzler, BAE Systems (United States)
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Quasi-phase-matched (QPM) materials periodically poled lithium niobate (PPLN) and tantalate (PPLT) have led to extremely efficient frequency-shifted laser sources in the visible and near-infrared, and QPM semiconductors promise to extend this performance beyond 4?m. Orientation patterned semiconductors are not only transparent far deeper into the mid-IR but also offer higher nonlinear coefficients, higher thermal conductivity, higher purity levels, and very low losses when grown from the vapor phase. We compare the properties, processing, and performance of orientation-patterned GaAs (OPGaAs) with emerging all-epitaxial-grown QPM semiconductors and present preliminary results on gallium phosphide (OPGaP).

Some properties of the mixed GaS0.4Se0.6 nonlinear crystal in comparison to GaSe

Paper 7917-51 of Conference 7917
Date: Thursday, 27 January 2011
Time: 1:35 PM ?1:55 PM

Author(s): Georgi Marchev, Aleksey Tyazhev, Vladimir L. Panyutin, Valentin P. Petrov, Frank Noack, Kentaro Miyata, Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie (Germany); Michael Griepentrog, Bundesanstalt für Materialforschung und -prüfung (Germany)
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It is possible to dope GaSe with up to 40% of S preserving its non-centrosymmetric structure in order to increase the band-gap and improve the thermo-mechanical properties. We present here Sellmeier equations for the mixed nonlinear crystal GaS0.4Se0.6 which were refined by fitting to SHG phase-matching angle data as well as birefringence data obtained with phase plates. We present also comparison of two-photon absorption data at 1064 nm for GaS0.4Se0.6 and GaSe obtained with picosecond pulses which indicates that GaS0.4Se0.6 could be used in Nd:YAG laser pumped OPOs and OPAs without nonlinear absorption. The microhardness is compared with nanoindentation tests.

High performance continuous-wave room temperature 4.0 祄 quantum cascade lasers with single-facet optical emission exceeding 2 watts

Paper 7953-55 of Conference 7953
Date: Thursday, 27 January 2011
Time: 2:00 PM ?2:20 PM

Author(s): Arkadiy A. Lyakh, Richard Maulini, Alexei G. Tsekoun, Rowel Go, Steven Von der Porten, Pranalytica, Inc. (United States); Christian J. Pflügl, Laurent Diehl, Federico Capasso, Harvard Univ. (United States); Chandra Kumar N. Patel, Pranalytica, Inc. (United States)
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A strain-balanced, AlInAs/InGaAs/InP quantum cascade laser structure, designed for light emission at 4.0 祄 using non-resonant extraction design approach, was grown by molecular beam epitaxy. Laser devices were processed in buried heterostructure geometry. An air-cooled laser system incorporating a 10 mm by 11.5 祄 laser with antireflection coated front facet and high reflection coated back facet delivered over 2 W of single-ended optical power in a collimated beam. Maximum continuous wave room temperature wallplug efficiency of 5.0% was demonstrated for a high reflection coated 3.65 mm by 8.7 祄 laser mounted on an aluminum nitride submount.

Highly power efficient distributed feedback quantum cascade lasers at 4.55 祄

Paper 7953-56 of Conference 7953
Date: Thursday, 27 January 2011
Time: 2:20 PM ?2:40 PM

Author(s): Mariano Troccoli, Xiaojun Wang, Jenyu Fan, AdTech Optics, Inc. (United States)
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Current challenges in small IR optical sensors and sensor networks for portable, lightweight system design are mostly related to the input power and heat dissipation required for laser operation. Battery life and operation in remote areas are greatly enhanced by devices with long lifetime, low power consumption, and requiring minimal system calibration and maintenance. For these reasons the prospect of highly efficient, low-power consuming distributed feedback (DFB) quantum cascade (QC) lasers, is very appealing for field applications both in environmental research and in industrial process control.In this paper we present our most recent results on DFB QC lasers operation.

High-throughput engineering of infrared plasmonic nanoantenna arrays with nanostencil lithography

Paper 7946-60 of Conference 7946
Date: Thursday, 27 January 2011
Time: 2:30 PM ?2:50 PM

Author(s): Serap Aksu, Ahmet A. Yanik, Ronen Adato, Alp Artar, Min Huang, Hatice Altug, Boston Univ. (United States)
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We will present a novel fabrication approach for low-cost and high-throughput fabrication of infrared plasmonic nanorod antenna arrays with Nanostencil Lithography (NSL). We show the optical responses of plasmonic antenna arrays fabricated by NSL are comparable to that of arrays fabricated by electron-beam lithography. In addition, nanostencils can be reused repeatedly to fabricate same antenna arrays with identical optical responses.We will show NSL offer sufficient flexibility and resolution to engineer nanoantenna arrays on variety of surfaces with designs providing collective plasmonic excitations, which are highly suitable for ultrasensitive vibrational nanospectroscopy.

Broadband quantum cascade laser arrays for mid-infrared spectroscopy

Paper 7953-57 of Conference 7953
Date: Thursday, 27 January 2011
Time: 2:40 PM ?3:00 PM

Author(s): Christian J. Pflügl, Laurent Diehl, Stefan Menzel, Romain Blanchard, Harvard Univ. (United States); Anish K. Goyal, Christine A. Wang, Antonio Sanchez, George W. Turner, MIT Lincoln Lab. (United States); Yong Huang, Jae-Hyun Ryou, Russell D. Dupuis, Georgia Institute of Technology (United States); Federico Capasso, Harvard Univ. (United States)
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Arrays of distributed-feedback quantum cascade lasers can be made as single-mode tunable high brightness sources covering a wide range of mid-infrared frequencies with applications in spectroscopy. We present recent developments in device and distributed feedback grating design leading to increased output power and improved single-mode selection of such arrays. * The Lincoln Laboratory portion of this work was sponsored by the Department of the United States Air Force under Air Force contract No. FA8721-05-C-0002. The opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the United States Government.


New mixed LiGa0.5In0.5Se2 nonlinear crystal for the mid-IR

Paper 7917-56 of Conference 7917
Date: Thursday, 27 January 2011
Time: 3:15 PM ?3:35 PM

Author(s): Vitaliy Vedenyapin, Ludmila I. Isaenko, Alexander P. Yelisseyev, Sergei Lobanov, Institute of Mineralogy and Petrography (Russian Federation); Aleksey Tyazhev, Georgi Marchev, Valentin P. Petrov, Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie (Germany)
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A new mixed nonlinear crystal, solid solution with the composition LiGa0.5In0.5Se2, is grown which exhibits the same mm2 orthorhombic structure as the parent compounds LiGaSe2 and LiInSe2. The unit cell parameters of LiGa0.5In0.5Se2 are a=7.0376(2) A, b=8.3401(3) A, and c=6.6855(2) A. The new crystal combines the easier growth of LiInSe2 with the deeper UV transparency of LiGaSe2. Its band gap is 3.2 eV. The dispersion characteristics were measured and Sellmeier equations will be presented. The fundamental wavelength range for the SHG process is 1.75-11.8 祄. The nonlinear coefficients of LiGa0.5In0.5Se2 will be compared with those of LiGaSe2 and LiInSe2.

Near-IR induced negative photoconductance and its relationship with optical quenching of mid-IR quantum cascade lasers (QCLs)

Paper 7953-62 of Conference 7953
Date: Thursday, 27 January 2011
Time: 4:50 PM ?5:10 PM

Author(s): Dingkai Guo, Liwei Cheng, Xing Chen, Fow-Sen Choa, Terrance Worchesky, Univ. of Maryland, Baltimore County (United States)
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We report the Near-IR induced negative photoconductance (NPC) on Mid-Infrared Quantum Cascade Lasers (QCLs) and its relationship with the optical quenching of the QCL. The NPC effect is affected by the Near-IR intensity and wavelength, the QCL bias voltage and the bias pulse width if the QCL is biased under pulse mode. The explanation of NPC is related to electron-hole generation and hole-trapping, which produces an internal field counteracting to the external field. The created band-bending effect will reduce the current, increase the resistance, and reduce the Mid-IR light output, which has been reported earlier as the "optical quenching effect".

Two-dimensional surface emitting single mode quantum cascade laser arrays

Paper 7953-72 of Conference 7953
Date: Thursday, 27 January 2011
Time: 5:30 PM ?5:50 PM

Author(s): Elvis Mujagic, Clemens Schwarzer, Werner Schrenk, Gottfried Strasser, Technische Univ. Wien (Austria); Yu Yao, Princeton Univ. (United States); Jianxin Chen, Shanghai Institute of Technical Physics (China); Claire F. Gmachl, Princeton Univ. (United States)
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We describe compact, two-dimensional single-mode quantum cascade laser arrays based on the ring cavity surface emitting laser, as a basic building block. The sixteen-element mid-infrared array shows a linear tuning range of ~180 cm-1 (7.5 - 8.7 祄) in pulsed condition at room temperature. The measured spectral dependent threshold current densities and optical power reflect the gain profile of the incorporated laser material. This suggests that the device performance is not affected by the individual grating design, given by the facetless nature of the incorporated single surface emitter. Such broadband laser arrays allow the realization of compact mid-infrared spectrometers.

Energy scaling of nanosecond gain-switched Cr2+:ZnSe lasers

Paper 7912-51 of Conference 7912
Date: Wednesday, 26 January 2011
Time: 3:10 PM ?3:30 PM

Author(s): Vladimir V. Fedorov, The Univ. of Alabama at Birmingham (United States) and IPG Photonics - Mid-Infrared Lasers (United States); Igor S. Moskalev, Mike B. Mirov, IPG Photonics - Mid-Infrared Lasers (United States); Sergey B. Mirov, The Univ. of Alabama at Birmingham (United States) and IPG Photonics - Mid-Infrared Lasers (United States); Torrey J. Wagner, Matthew J. Bohn, Air Force Institute of Technology (United States); Patrick A. Berry, Kenneth L. Schepler, Air Force Research Lab. (United States)
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In this paper, we report record nanosecond output energies of gain-switched Cr:ZnSe lasers pumped by Q-switched Cr:Tm:Ho:YAG (100ns@2.096祄) and Raman shifted Nd:YAG lasers (7ns@1.906祄). In these experiments we used Brewster cut Cr:ZnSe gain elements with a chromium concentration of 8x1018 cm-3. Under Cr:Tm:Ho:YAG pumping, the first Cr:ZnSe laser demonstrated 3.1 mJ of output energy, 52% slope efficiency and 110 nm linewidth centered at a wavelength of 2.47 祄. Maximum output energy of the second Cr:ZnSe laser reached 10.1 mJ under H2 Raman shifted Nd:YAG laser pumping. The slope efficiency estimated from the input-output data was 47%.

Efficient generation of coherent mid-infrared and far-infrared waves in highly lossy second-order nonlinear media at polariton resonances under transverse-pumping geometry

Paper 7937-53 of Conference 7937
Date: Wednesday, 26 January 2011
Time: 8:25 AM ?8:50 AM

Author(s): Yujie J. Ding, Lehigh Univ. (United States)
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Due to strong coupling between transverse-optical phonons and mid-infrared or far-infrared waves, second-order nonlinear coefficients are dramatically enhanced within the forbidden band of each polariton resonance. Transverse-pumping geometry is exploited for achieving efficient mid-infrared and far-infrared generation at each resonance. A pump power of 100 mW is sufficient for efficient conversion.

Efficacy of near-infrared spectroscopy in monitoring and detection of skeletal muscle ischemia

Paper 7883F-123 of Conference 7883F
Date: Saturday, 22 January 2011
Time: 9:00 AM ?9:20 AM

Author(s): R. Luke Harris, Univ. of Northern British Columbia Prince George Campus (Canada); Babak Shadgan M.D., UBC Muscle Biophysics Lab. (Canada); W. Darlene Reid, UBC Muscle Biophysics Lab. (Canada) and The Univ. of British Columbia (Canada); Peter J. O'Brien, The Univ. of British Columbia (Canada)
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The purpose of this study was to examine the efficacy of near-infrared spectroscopy (NIRS) for monitoring tourniquet-induced ischemia of leg muscles during trauma surgery. Changes in oxygenated (O2Hb), and deoxygenated (HHb) hemoglobin in tourniquet-affected leg muscles of 21 patients with ankle fractures were monitored by a continuous wave NIRS. Following tourniquet inflation a consistent progressive increase in HHb with a concomitant decrease in O2Hb in the tourniquet-affected muscle were observed amongst subjects. Duration of ischemia was significantly correlated to ?HHb, ?O2Hb and oxygenation recovery time. Our findings confirmed efficacy of NIRS in detection and monitoring of skeletal muscle ischemia.

Dual-modality catheter for optical frequency domain imaging and near-infrared fluorescence imaging

Paper 7883D-77 of Conference 7883D
Date: Saturday, 22 January 2011
Time: 11:20 AM ?11:40 AM

Author(s): HongKi Yoo, Jin Won Kim, Milen S. Shishkov, Eman namati, Massachusetts General Hospital (United States); Theodore F. Morse, The Boston Univ. Photonics Ctr. (United States); Roman L. Shubochkin, Boston Univ. (United States); Jason R. McCarthy, Brett E. Bouma, Farouc A. Jaffer M.D., Guillermo J. Tearney, Massachusetts General Hospital (United States)
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We report a dual modality intra-arterial catheter system that simultaneously obtains co-registered optical frequency domain imaging (OFDI) and near-infrared fluorescence (NIRF) imaging from artery wall in vivo. The catheter is comprised of a double-clad fiber, contained within a rotating cable and a transparent sheath. Comprehensive 3D datasets were acquired from a coronary stent, deployed in an iliac artery of a living rabbit. The results clearly delineate the microstructures of the luminal arterial wall, metallic stent struts, and thrombus as well as NIRF emission. The NIRF signals show strong correspondence with the OFDI. This novel catheter could open up new opportunities for improving our understanding of coronary atherosclerosis.

Photothermal imaging through coherent infrared bundles

Paper 7894-47 of Conference 7894
Date: Sunday, 23 January 2011
Time: 11:50 AM ?12:10 PM

Author(s): Yonat Milstein, Michal Tepper, Moshe Ben-David, Tel Aviv Univ. (Israel); Jim Harrington, Rutgers, The State Univ. of New Jersey (United States); Israel Gannot, Tel Aviv Univ. (Israel) and Johns Hopkins Univ. (United States)
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Development of optical fiber head probes for infrared endoscopic medical diagnosis

Paper 7894-40 of Conference 7894
Date: Sunday, 23 January 2011
Time: 3:30 PM ?3:50 PM

Author(s): Marie-Laure Anne, Univ. de Rennes 1 (France); P. Houizot, Univ de Rennes I (France); Bruno Bureau, Univ. de Rennes 1 (France); O. Loréal, INSERM (France); V. Monbet, Univ. de Bretagne Sud (France); C. Boussard-Plédel, J. Lucas, Univ. de Rennes 1 (France)
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Thanks to the development of chalcogenide glass fiber, transmitting light in the infrared range, the infrared spectroscopy can be carried out in situ by Fiber Evanescent Wave Spectroscopy, so-called FEWS. FEWS has proved to be a powerful technology for the study of biomedical samples, in particular for the detection of foodborne pathogens in the food processing industries and for non invasive diagnosis in the medical domain. Recent important progress in the quality and the design of chalcogenide fibers have enabled to obtain optical fiber with a miniaturized head-probe which can be used for endoscopic measurements. FEWS coupled to chemometric methods, such as PCA and PLS, allowed to differentiate between, for instance, healthy and non healthy tissue on human body biological liquid. Thus, FEWS carried out with chalcogenide optical fiber is becoming an efficient tool for physician.

Application of spectral derivative data in near-infrared spectroscopic tomography

Paper 7896-17 of Conference 7896
Date: Sunday, 23 January 2011
Time: 4:20 PM ?4:40 PM

Author(s): Hamid Dehghani, The Univ. of Birmingham (United Kingdom); Frederic Leblond, Brian W. Pogue, Dartmouth College (United States); Fabien Chauchard, Indatech (France)
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The use of the spectral derivative method in Near Infrared optical spectroscopy and tomogrphic imaging is presented, whereby instead of using discrete measurements around several wavelengths, the difference between nearest neighbouring spectral measurements are used. The proposed technique is shown to be insensitive to the unknown tissue and fibre contact coupling coefficients providing substantially increased accuracy as compared to more conventional techniques. The self-calibrating nature of the spectral derivative techniques increases its robustness in clinical applications, as is demonstrated based on simulated results as well as experimental data.

Process analytical applications in the mid-infrared

Paper 7945-23 of Conference 7945
Date: Sunday, 23 January 2011
Time: 4:25 PM ?4:45 PM

Author(s): Stefan H. Lundqvist, Pawel Kluczynski, Siemens Laser Analytics AB (Sweden)
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We will present work on tunable diode laser spectroscopy of hydrocarbons in the 3 micron wavelength region using novel GaSb DFB lasers. A number of suitable process analytical applications especially in ethylene and propylene manufacturing have been investigated. Detection of acetylene impurities in ethylene in a gas matrix typical of a hydrogenating reactor has been performed. The performance for detection of acetylene impurities in pure ethylene using a TDLS sensor was better than 18 ppm*m for a response time of 3 seconds. Experience from in-situ measurements of hydrocarbons in an industrial environment using a cross duct instrument will also be presented.

Calibration methods of frequency domain measurement system with near-infrared diffused light

Paper 7891-32 of Conference 7891
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Huijuan Zhao, Ying Fan, Xiaoqing Zhou, Julan Liang, Tingting Wang, Feng Gao, Tianjin Univ. (China)
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Optical diagnostics has the potential to provide real-time diagnosis of tissue noninvasively. Frequency domain (FD) near-infrared diffuse spectroscopy (NIRS) is one of the three common techniques in NIRS field. This article deals with the method for eliminating or calibrating the intrinsic parameters of the FD measurement system, which include the intrinsic amplitude attenuation and intrinsic phase delay. Several calibration methods are proposed and a method is also proposed to eliminate the optode coupling coefficient, which is the main source of the inaccuracy in FD measurement. Endoscopic measurements on two solid tubular phantoms with known optical properties are adopted to evaluate the proposed calibration methods.

Near-infrared imaging of teeth at wavelengths between 1200 and 1600 nm

Paper 7884-33 of Conference 7884
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Soojeong Chung, Daniel Fried, Cynthia L. Darling, Univ. of California, San Francisco (United States)
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Time-gated near-infrared spectroscopic imaging of brain activation: a simulation proof of concept

Paper 7896-80 of Conference 7896
Date: Sunday, 23 January 2011
Time: 5:30 PM

Author(s): Gilberto Diaz-Ayil, Farouk Nouizi, Univ. de Strasbourg (France); Wilfried Uhring, Benoit Dubois, Institut d'Électronique du Solide et des Systèmes (France); Patrick Poulet, Univ. de Strasbourg (France)
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3 companies and 2 academic laboratories merged their skills to build a spectroscopic imaging device, without any scan and any contact, to study brain activation in normal humans and patients. The whole area of interest will be illuminated with picosecond laser pulses at different wavelengths. The scattered photons will be detected in a reflectance mode, with a time gated intensified CCD camera. We will describe the basics and the results of a time resolved 3D simulation study performed in order to evaluate the sensitivity and the accuracy of the proposed method for brain activation imaging.

Gold nanorods in photodynamic therapy as hyperthermia agents, and in near-infrared optical imaging

Paper 7910-8 of Conference 7910
Date: Monday, 24 January 2011
Time: 11:00 AM ?11:20 AM

Author(s): Wen-Shuo Kuo, Chich-Neng Chang, Yi-Ting Chang, National Cheng Kung Univ. (Taiwan); Meng-Heng Yang, National Chung Hsing Univ. (Taiwan); Yi-Hsin Chien, Shean-Jen Chen, Chen-Sheng Yeh, National Cheng Kung Univ. (Taiwan)
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We have successfully conjugated an NIR photosensitizer, ICG, on the surface of Au nanorods. The resulting Au-PSMA-ICG nanorods act as PDT and hyperthermia agents. Combined PDT and hyperthermia not only kills cancer cells more efficiently than PDT or hyperthermia treatment alone, but also improves the efficacy of photodestruction and acts as an effective bio-imaging probe in the NIR region.

Infrared laser stimulation of retinal and vestibular neurons

Paper 7883G-137 of Conference 7883G
Date: Monday, 24 January 2011
Time: 11:00 AM ?11:20 AM

Author(s): Fabrice Bardin, Univ des Nîmes (France) and Univ. Montpellier 2 (France); Jean-Michel Bec, Univ. Montpellier 2 (France); Emmanuelle S. Albert, Christian Chabbert, Christian Hamel, Institut des Neurosciences de Montpellier (France); Gerard Dupeyron, Ctr. Hospitalier Univ. de Nimes (France); Isabelle Marc, Ecole des Mines d'Ales (France) and Univ. Montpellier 2 (France); Michel Dumas, Univ. Montpellier 2 (France)
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The study of laser-neuron interaction has gained interest over the last few years not only for understanding of fundamental mechanisms but also for medical applications such as prosthesis because of the laser stimulation non-invasive characteristic. We present in this work biological responses from calcium fluorescence imaging and electrophysiological recordings on cultured vestibular and retinal ganglion cells triggered by infrared laser pulses. Effects of different wavelengths (from 1470 to 1875 nm) and stimulation duration have been investigated. Stimulation energy thresholds and temperature measurements show that heat-activated membrane channels could be stimulated, supporting the hypothesis of a photothermal stimulation of ion channels.

Infrared plasmonic detectors

Paper 7945-39 of Conference 7945
Date: Monday, 24 January 2011
Time: 11:00 AM ?11:20 AM

Author(s): Nicolas Péré-Laperne, Stéphane S. Collin, Fabrice Pardo, Jean-Luc Pelouard, Ctr. National de la Recherche Scientifique (France)
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Since 2002, plasmonic has demonstrated the ability to enhance performances of photodetectors at a resonant wavelength. Absorption in a photodetector can reach 100% using nanophotonic plasmonic array. Plasmonic devices are confining light at the interface metal/dielectric, as a consequence, detection volume is smaller (100 to 1000 times) than in usual photodetectors leading to a decrease in dark current of infrared photodetectors and therefore a higher working temperature. The second consequence of a short detection volume is a higher collection efficiency of photocarriers as the transit time is smaller than the lifetime. We are working on the enhancement of different quantum infrared devices using plasmonic array. Both theoretical and experimental results will be presented.

Course: Coherent Mid-Infrared Sources and Applications

Date: Monday, 24 January 2011
Time: 1:30 PM ?5:30 PM

Instructor(s): Konstantin L. Vodopyanov, Stanford Univ. (United States)
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This course explains why the mid-IR spectral range is so important for molecular spectroscopy, standoff sensing, and trace molecular detection. We will regard different approaches for generating coherent light in the mid-IR including solid state lasers, fiber lasers, semiconductor (including quantum cascade) lasers, and laser sources based on nonlinear optical methods. The course will discuss several applications of mid-IR coherent light: spectral recognition of molecules, trace gas sensing, standoff detection, and frequency comb Fourier transform spectroscopy.

Feasibility of rapid near-infrared diffuse optical tomography by swept-spectral-encoded sequential light delivery

Paper 7896-31 of Conference 7896
Date: Monday, 24 January 2011
Time: 2:10 PM ?2:30 PM

Author(s): Guan Xu, Daqing Piao, Oklahoma State Univ. (United States)
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We investigate the feasibility of rapid near infrared DOT by spectrally-encoded sequential light delivery using wavelength-swept source. The wavelength-swept light beam is dispersed by a spectrometer to form "swept-spectral-encoding" of the light beam which scans linearly across the exit window of the spectrometer and delivers sequential illumination to linearly bundled source fibers. A data acquisition rate of over 1 frame/second is reached from a 4mW swept-source and a 20mm-diameter intra-lumenal applicator with 8 source and 8 detector channels. This new configuration can be readily extended to rapid fluorescence diffuse optical tomography (FDOT) by enabling sequential source-channel-encoded excitations of fluorophores.

Thermal effect induced by interstitial irradiation of near-infrared laser with cylindrical diffuser

Paper 7900-10 of Conference 7900
Date: Monday, 24 January 2011
Time: 2:50 PM ?3:10 PM

Author(s): Wei R. Chen, Daniel Figueroa, Kelvin Le, Univ. of Central Oklahoma (United States); Xiaosong Li, Chinese PLA General Hospital (China); Jonny Walla, Univ. of Central Oklahoma (United States); Roman F. Wolf, The Univ. of Oklahoma Health Sciences Ctr. (United States); Hong Liu, The Univ. of Oklahoma (United States); Robert E. Nordquist, Wound Healing of Oklahoma, Inc. (United States); Tomas L. M. Hode, Immunophotonics, Inc. (United States)
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The present study is designed to investigate the thermal effect of interstitial irradiation using an 805-nm laser with a cylindrical diffuser, in order to overcome the limitations of the non-invasive mode of treatment. Gel phantom, chicken breast tissue, bovine liver and pig kidney, as well as in vivo rat tumors were irradiated using this system. The temperature increase was monitored by thermocouples that were inserted into the tissue at different sites around the cylinder fiber. Three-dimensional temperature distributions in target tissues during and after interstitial laser irradiation were also determined by magnetic resonance thermometry. The preliminary results showed that the output power of laser and the optical parameters of the target tissue determined the light distribution in tissue. These results will help us understand and control the thermal effect induced by interstitial laser irradiation.

Optical path of infrared neural stimulation in the guinea pig cochlea

Paper 7883G-160 of Conference 7883G
Date: Monday, 24 January 2011
Time: 3:10 PM ?3:30 PM

Author(s): Laura E. Moreno, Suhrud M. Rajguru, Agnella I. Matic, Nitin Yerram, Alan M. Robinson, Claus-Peter Richter, Northwestern Univ. (United States)
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It has been demonstrated previously that infrared neural stimulation (INS) can be utilized to stimulate spiral ganglion cells in the cochlea. Although neural stimulation can be achieved without direct contact of the radiation source and the tissue, the presence of fluids or bone between the target structure and the radiation source may lead to absorption or scattering of the radiation. Absorption or scattering of radiation may limit the efficacy of INS. The present study demonstrates that only neural structures in the beam path are stimulated. The histological reconstructions of guinea pig cochleae stimulated with INS suggest that the orientation of the beam from the optical fiber determined the site of stimulation in the cochlea. Best frequencies of the neural responses obtained from the central nucleus of the inferior colliculus matched the histological site in the spiral ganglion. Overall, the results indicated that the stimulated structures in the cochlea are the spiral ganglion cells and not the nerve fibers in the center of the modiolus.

Pulse shape effects on cochlear responses during infrared neural stimulation

Paper 7883G-161 of Conference 7883G
Date: Monday, 24 January 2011
Time: 3:30 PM ?3:50 PM

Author(s): Renee Banakis, Agnella I. Matic, Suhrud M. Rajguru, Claus-Peter Richter, Northwestern Univ. (United States)
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Infrared neural stimulation (INS) has been shown to be effective in several neural systems, including peripheral motor nerves, the cortex, and the cochlea. The leading premise for INS mechanism is that neural depolarization occurs secondary to a spatially and temporally restricted photothermal interaction. In other words, a transient temperature rise needs to occur in the tissue to induce neural stimulation. Several studies have investigated the variability of evoked responses with different optical parameters. In part, this is motivated by an interest in minimizing the temperature increase that occurs in the tissue, which is directly correlated with the amount of energy that is deposited. In this study, we examined the effect of pulse waveform on the evoked responses of INS in the cochlea. Pulse waveforms, such as square and triangular pulses with different rise times, were tested. Energy, power, and temporal properties of each pulse were verified optically. Cochlear compound action potentials (CAPs) were recorded from acutely deafened gerbils. The data were analyzed for CAP threshold and maximum CAP amplitude.

Analysis of near-infrared auto-fluorescence peak found in parathyroid and thyroid tissues

Paper 7890-18 of Conference 7890
Date: Monday, 24 January 2011
Time: 3:40 PM ?4:00 PM

Author(s): Constantine Paras, Lisa White, James Broome, Vanderbilt Univ. (United States); Edward M. Brown, Brigham and Women's Hospital (United States); Anita Mahadevan-Jansen, Vanderbilt Univ. (United States)
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Complications such as postoperative hypocalcemia and hypo-parathyroidism can occur due to accidental or incomplete removal of parathyroid glands during endocrine surgery. Initial fiber probe measurements have shown that the parathyroid exhibits markedly higher levels of near-infrared autofluorescence in comparison to all other tissues in the neck. While there are no biological fluorophores reported in the literature expressed by thyroid and parathyroid tissue to explain the documented fluorescence, examination of the anatomy points to several possible candidates. Fluorescence, tissue and protein analysis were performed to assess the likelihood of the different potential fluorophores.

Multi-physics system performance model for numerical simulations of infrared nerve stimulation

Paper 7883G-191 of Conference 7883G
Date: Monday, 24 January 2011
Time: 3:50 PM ?4:10 PM

Author(s): Matthew Keller, Bryan Norton, Lockheed Martin Aculight (United States); Claus-Peter Richter, Agnella Izzo-Matic, Suhrud M. Rajguru, Northwestern Univ. (United States); Jonathon D. Wells, Lockheed Martin Aculight (United States)
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Infrared nerve stimulation (INS) is the result of a laser-induced spatio-temporal temperature gradient. A multi-physics system performance model was developed to simulate all physical processes associated with INS, with the objective of identifying optimal laser parameters for stimulating nerves without causing damage. The model performs these steps: light delivery using ray-tracing; absorption/scattering of photons via Monte Carlo simulations; and heat accumulation/dissipation from both absorption of photons and device-generated heat with a finite difference model. It has been used to predict the number of allowable channels in an INS-based cochlear implant, and to examine extraneural vs intrafascicular approaches for peripheral nerves.

Near-infrared fluorescence imaging of lymphatics in head and neck lymphedema

Paper 7890-19 of Conference 7890
Date: Monday, 24 January 2011
Time: 4:00 PM ?4:20 PM

Author(s): I-Chih Tan, Erik A. Maus, John C. Rasmussen, Milton V. Marshall, Caroline E. Fife, Latisha A. Smith, Eva M. Sevick-Muraca, The Univ. of Texas Health Science Ctr. at Houston (United States)
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Treatment of lymphedema (LE) could be complicated, especially in regions where treatment options are limited. We present a study in a patient with head and neck LE. Immediately after intradermal injections of indocyanine green, near-infrared (NIR) fluorescence images of lymphatics around face and neck were collected. Also, 3-dimensional (3D) surface profilometry was used to monitor response to manual lymphatic drainage (MLD) therapy. NIR fluorescence imaging provides a mapping of functional lymphatic vessels and abnormal structures for direction of effective MLD therapy, and longitudinal assessment of edema to evaluate the efficacy of therapy was achieved using 3D profilometry.


Sub-100-nm material processing with sub-15-femtosecond picojoule near-infrared laser pulses

Paper 7903-54 of Conference 7903
Date: Tuesday, 25 January 2011
Time: 8:00 AM ?8:20 AM

Author(s): Karsten Koenig, Aisada A. Uchugonova, Martin H. Straub, Huijing Zhang, Maziar Afshar, Dara Feili, Helmut Seidel, Univ. des Saarlandes (Germany)
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Ultrabroad band in situ 12 femtosecond near infrared laser pulses at transient TW/cm2 intensities and low picojoule pulse energies (mean powers < 20 mW at 85 MHz repetition rate) have been used to perform 3D material nanoprocessing based on multiphoton ionization and plasma formation. Cut sizes of sub-wavelength, sub-100 nm which is far beyond the Abbe diffraction have been realized without any collateral damage effect in silicon wafers, photoresists, glass, metals, and biological targets. Acknowledgments: The authors wish to thank the German Science Foundation (Key Program 1327) for financial support.

Nanosurgery with near-infrared femtosecond and picosecond laser pulses

Paper 7903-55 of Conference 7903
Date: Tuesday, 25 January 2011
Time: 8:20 AM ?8:40 AM

Author(s): Aisada A. Uchugonova, Huijing Zhang, Karsten Koenig, Univ. des Saarlandes (Germany)
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Laser-assisted surgery based on multiphoton absorption of NIR light has great potential for high precision surgery at various depths within the cells and tissues. Especially such non-contact method supports contamination-free cell surgery. Here we apply femtosecond laser scanning microscopes for sub-100 nm surgery of human cells and metaphase chromosomes. A mode-locked 85 MHz Ti:Sapphire laser with an M-shaped ultrabroad band spectrum (maxima: 770 nm/830 nm) with an in situ pulse duration at the target of 12 femtoseconds up to 3 picoseconds due to the introduction of chirped mirrors, flint glass wedges, and glass blocks was employed. The results of laser nanoprocessing in cell/chromosome structures have been quantified by atomic force microscopy (AFM) and electron microscopy. These studies demonstrate the potential of extreme ultrashort femtosecond laser pulses at low mean milliwatt powers for sub-100 nm surgery.

Temperature dependence of the key electro-optical characteristics for mid-infrared emitting quantum cascade lasers

Paper 7953-22 of Conference 7953
Date: Tuesday, 25 January 2011
Time: 11:40 AM ?12:10 PM

Author(s): Dan Botez, Univ. of Wisconsin-Madison (United States); Sushil Kumar, Massachusetts Institute of Technology (United States); Jae-Cheol Shin, Luke J. Mawst, Univ. of Wisconsin-Madison (United States); Igor Vurgaftman, Jerry R. Meyer, U.S. Naval Research Lab. (United States)
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The equations for threshold-current density Jth, differential quantum efficiency ?d and maximum wallplug efficiency ?wp.max for quantum-cascade lasers (QCLs) are modified for electron leakage and backfilling. For conventional mid-infrared QCLs ?wp.max is found to be strongly temperature dependent; explaining experimental data. We use a thermal-excitation model of "hot" injected electrons from the upper laser state to upper active-region energy states to calculate leakage currents. The characteristic temperature T0 for Jth is estimated and found to agree well with experiment for both conventional and deep-well (DW) QCLs. At 300 K, for DW-QCLs, front-facet, CW ?wp.max values > 20 % are estimated.

Subsurface temperature imaging techniques during infrared laser-tissue interactions

Paper 7897-32 of Conference 7897
Date: Tuesday, 25 January 2011
Time: 1:30 PM ?1:50 PM

Author(s): Rudolf M. Verdaasdonk, Vrije Univ. Medical Ctr. (Netherlands); Stefan Been, John H. Klaessens, Univ. Medical Ctr. Utrecht (Netherlands)
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A new strategy has been developed obtain thermal images below the surface of biological tissue by viewing through a ZincSelenide window to study and obtain a better understanding of the thermo dynamics during laser-tissue interaction of various IR lasers and delivery systems. In addition, high speed color Schlieren imaging was applied to visualize temperature gradients in a transparent tissue model. The thermal, high speed and normal imaging techniques showed to be both compatible and complementary. The subsurface thermal imaging enable comparison and better understanding of the tissue effects between various continuous wave and pulsed IR laser systems and delivery systems.

Near-infrared optical mammography with broadband spectral imaging and depth discrimination

Paper 7896-52 of Conference 7896
Date: Tuesday, 25 January 2011
Time: 2:10 PM ?2:30 PM

Author(s): Yang Yu, Angelo Sassaroli, Tufts Univ. (United States); Marc J. Homer, Roger A. Graham, Tufts Medical Ctr. (United States); Sergio Fantini, Tufts Univ. (United States)
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We have previously reported the development of an instrument for diffuse spectral imaging of the human breast operating over the wavelength range 650-900 nm. We have now implemented depth discrimination capabilities by introducing two additional collection optical fibers that are off-axis in the x and y directions, respectively, with respect to the illumination optical fiber. Validation of the new depth discrimination capabilities has been performed on tissue-like phantoms. We report depth resolved images of healthy human breasts and initial clinical results on cancer-bearing breasts that show the potential of our spectral oxygenation imaging approach combined with depth discrimination.

Skin damage thresholds with continuous-wave laser exposures at the infrared wavelength of 1.3 祄

Paper 7897-35 of Conference 7897
Date: Tuesday, 25 January 2011
Time: 2:30 PM ?2:50 PM

Author(s): Jeffrey W. Oliver, Semih S. Kumru, Robert J. Thomas, Benjamin A. Rockwell, Air Force Research Lab. (United States); Corey A. Harbert, Gary D. Noojin, Isaac Noojin, Kurt J. Schuster, Aurora D. Shingledecker, TASC, Inc. (United States)
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Damage thresholds (ED50) for skin using Yucatan mini-pig (Sus scrofa domestica) have been determined at the operational wavelength of 1.3 um with beam diameters of 0.61 cm and 0.95 cm. Exposure durations of 0.25, 1.0, 2.5 and 10 seconds were used to determine trends in damage threshold with respect to exposure time and beam diameter at this moderately penetrating wavelength. A relatively narrow range of total radiant exposure from 19.3 J/cm^2 to 30.5 J/cm^2 was observed for threshold damage with laser parameters encompassing a factor of two in beam area and a factor of forty in exposure duration.

Tunable mid-infrared filter based on Fabry-Pérot interferometer with two movable reflectors

Paper 7930-18 of Conference 7930
Date: Tuesday, 25 January 2011
Time: 2:30 PM ?2:50 PM

Author(s): Marco Meinig, Steffen Kurth, Fraunhofer-Institut für Einrichtung Elektronische Nanosysteme (Germany); Karla Hiller, Technische Univ. Chemnitz (Germany); Norbert Neumann, Martin Ebermann, InfraTec GmbH (Germany); Elvira Gittler, JENOPTIK Optical Systems GmbH (Germany); Thomas Gessner, Fraunhofer-Institut für Einrichtung Elektronische Nanosysteme (Germany) and Technische Univ. Chemnitz (Germany)
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Tunable wavelength range, wavelength selectivity, maximum actuation voltage and robustness against gravitation and vibration are key specifications of electrically tunable infrared filters for small-sized infrared analysis systems. Here, a novel FPI based tunable IR filter with two movable reflectors is reported. A low stiffness suspension of both reflectors leads to compensation of vibration and gravitation induced forces on the central wavelength, and much lower actuation voltages (30 V) as a result for a tuning range from 10.2 祄 to 8 祄, with 150 nm FWHM bandwidth and 70 % peak transmittance. The device withstands 1500 g, 0.5 ms shocks.

Chromophores design for nonlinear optics in the near infrared

Paper 7935-26 of Conference 7935
Date: Tuesday, 25 January 2011
Time: 3:30 PM ?4:00 PM

Author(s): Chantal Andraud, Ecole Normale Supérieure de Lyon (France)
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We present approaches for the design of fluorescent probes featuring high two-photon absorption (TPA) cross-sections : -using the luminescence properties of LnIII ions, we designed a new family of ligands-based chromophores inducing lanthanides emission by two-photon antenna. Two-photon scanning microscopy bio-imaging with these complexes led to consider them as a new generation of probes . - photodynamic therapy capability of chromophores, stabilizing triplet states for singlet oxygen generation combined with TPA properties, was shown. - to develop probes for second-harmonic generation and two-photon excited fluoresecence microscopies, we proposed a series of neutral push-pull probe molecules, fulfilling the right balance between hydrophobicity and hydrophilicity, for which a good membrane staining could be observed.

Nanostructure formation on silicon surfaces by high repetition-rate sub-15fs near-infrared laser pulses

Paper 7920-26 of Conference 7920
Date: Tuesday, 25 January 2011
Time: 4:40 PM ?5:00 PM

Author(s): Martin H. Straub, Karsten König, Univ. des Saarlandes (Germany)
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On low-indexed crystalline silicon surfaces characteristic micro- and nanostructures are formed using high repetition-rate sub-15 fs Ti:Sapphire laser pulses. Sub-nJ pulse energies efficiently induce profound structural and compositional changes in the high-numerical aperture focus of our laser scanning microscope. For example, a Si(100) surface exposed to laser light in water revealed periodic changes in morphology involving oxide particle formation and sub-10 nm hole arrangements, whereas a similar experiment in oil resulted in nano-scale deposition of carbon compounds. We present novel investigations as well as analysis and discussion of phenomena and compare results with observations made using longer pulse widths.

Nanostructure formation on silicon surfaces by high repetition-rate sub-15fs near-infrared laser pulses

Paper 7925-26 of Conference 7925
Date: Tuesday, 25 January 2011
Time: 4:40 PM ?5:00 PM

Author(s): Martin H. Straub, Karsten König, Univ. des Saarlandes (Germany)
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On low-indexed crystalline silicon surfaces characteristic micro- and nanostructures are formed using high repetition-rate sub-15 fs Ti:Sapphire laser pulses. Sub-nJ pulse energies efficiently induce profound structural and compositional changes in the high-numerical aperture focus of our laser scanning microscope. For example, a Si(100) surface exposed to laser light in water revealed periodic changes in morphology involving oxide particle formation and sub-10 nm hole arrangements, whereas a similar experiment in oil resulted in nano-scale deposition of carbon compounds. We present novel investigations as well as analysis and discussion of phenomena and compare results with observations made using longer pulse widths.

Application of near-infrared fluorescence imaging to monitor changes in HER2 expression after therapeutic intervention

Paper 7910-35 of Conference 7910
Date: Tuesday, 25 January 2011
Time: 5:00 PM ?5:20 PM

Author(s): Victor V. Chernomordik, Moinuddin Hassan, Rafal Zielinski, Amir H. Gandjbakhche, Jacek Capala, National Institutes of Health (United States)
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A method to quantify the overexpression of HER2 receptor in the tumor is suggested. Quantitative in vivo NIR optical imaging of xenografts mice with subcutaneous HER2-positive tumors was performed. Fluorescence images were obtained at several time points after intravenous injection of the dye to investigate binding kinetics. Compartmental ligands-receptor model was used to estimate HER2 expression from data, obtained with HER2-specific contrast agent, and monitor treatment with 17-DMAG. Initial slope, characterizing the temporal dependence of the fluorescence intensity, detected in the tumor, linearly depends on the HER2 expression, measured ex vivo by an ELISA assay for the same tumor.

Progress in Sb-based type II superlattice infrared detector technology and minority carrier lifetime study

Paper 7945-70 of Conference 7945
Date: Wednesday, 26 January 2011
Time: 9:05 AM ?9:25 AM

Author(s): Sumith Bandara, Meimei Z. Tidrow, U.S. Army Night Vision & Electronic Sensors Directorate (United States)
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Type-II Superlattice detector (T2SL) technology for IR detection has progressed significantly, demonstrating experimentally potential as a strong candidate for future high-performance IR sensors. This paper will discuss recent improvements in device design such as the inclusion of wide-gap based p-n junctions and optimization of the doping profile in the active layer of the detector. In addition, advances in device processing, specifically in dry-etch techniques, have culminated detector arrays with nearly vertical mesa walls. Despite recent progress, current T2SL detector performance appears to be limited by the shorter minority carrier lifetime associated with the generation-recombination process. This paper will analyze T2SL's quantum efficiency and dark current based on various aspects of the device such as diffusion, generation-recombination and tunneling, and dependence on the minority carrier lifetime of T2SL detector material. This analysis will allow us to predict the detector performance as a function of minority carrier lifetime and possible improvements resulting from T2SL's flexible bandgap-engineered growth capability. The paper will also present experimental measurements of minority carrier lifetime of T2SL detectors.

Near-infrared pulsed light to guide prostate biopsy

Paper 7895-23 of Conference 7895
Date: Wednesday, 26 January 2011
Time: 9:50 AM ?10:10 AM

Author(s): Jérôme Boutet, Aurelie Laidevant, Lionel Hervé, Mathieu Debourdeau, Commissariat à l'Énergie Atomique (France); Didier Vray, CREATIS-LRMN INSA (France); Jean-Marc Dinten, Commissariat à l'Énergie Atomique (France)
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A combined ultrasound and optical endorectal probe was designed to comply with the constraints of the sterilization protocols, the examination duration and required compactness. Therefore a totally innovative pulsed laser source has been designed to meet compactness requirements while providing accurate time-resolved measurements. A dedicated multi-channel photon counting system was optimized to decrease the examination duration. A fast reconstruction method based on the analysis of the intensity and time of flight of the detected photons has been associated to provide 3D localization of fluorescent dots almost immediately after acquisition.

Potential of carbon nanotubes films for infrared bolometers

Paper 7945-75 of Conference 7945
Date: Wednesday, 26 January 2011
Time: 11:00 AM ?11:20 AM

Author(s): Charlie Koechlin, Sylvain B. Maine, ONERA (France) and Ctr. National de la Recherche Scientifique (France); Stéphanie Rennesson, Riad Haïdar, B. Tretout, Julien Jaeck, ONERA (France); Nicolas Péré-Laperne, Jean-Luc Pelouard, Ctr. National de la Recherche Scientifique (France)
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Development of chipscale chalcogenide glass based infrared chemical sensors

Paper 7945-86 of Conference 7945
Date: Wednesday, 26 January 2011
Time: 4:30 PM ?4:50 PM

Author(s): Juejun Hu, Univ. of Delaware (United States); J. David Musgraves, Clemson Univ. (United States); Nathan Carlie, Clemson Univ. (Albania); Bogdan Zdyrko, Igor Luzinov, Clemson Univ. (United States); Anuradha M. Agarwal, Massachusetts Institute of Technology (United States); Kathleen Richardson, Clemson Univ. (United States); Lionel C. Kimerling, Massachusetts Institute of Technology (United States)
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In this talk, we will review the design, processing, and characterization of novel planar infrared chemical sensors. Chalcogenide glasses are identified as the material of choice for sensing given their wide infrared transparency as well as almost unlimited capacity for composition alloying and property tailoring. We show that high-Q chalcogenide glass micro-disk optical resonant cavities can operate in several sensing modes where different molecular species are detected using distinctive yet complementary mechanisms. As a consequence, molecules can be sensed with improved detection sensitivity and specificity. We further illustrate that resonant cavities can also serve as an ideal device platform for cavity-enhanced opto-mechanical interactions, which potentially enables multi-functional molecular manipulation and detection.

Efficient vertical-cavity surface-emitting lasers for infrared illumination applications

Paper 7952-15 of Conference 7952
Date: Wednesday, 26 January 2011
Time: 4:40 PM ?5:00 PM

Author(s): Jean-Francois Seurin, Guoyang Xu, Baiming Guo, Alexander Miglo, Qing Wang, Prachi Pradhan, James D. Wynn, Viktor Khalfin, Wei-Xiong Zou, Chuni Ghosh, Robert Van Leeuwen, Princeton Optronics, Inc. (United States)
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Infrared illumination is used in the commercial and defense markets for surveillance, security, and military covert operations. Vertical-cavity surface-emitting lasers (VCSELs) are an attractive candidate for illumination applications, as they offer advantageous properties such as efficiency, low diverging circular beam, low-cost manufacturing, narrow spectrum, and reliability. We will present results on VCSEL single devices and large arrays for illumination applications, as well as results on VCSEL-based illumination experiments. These VCSELs emit from a few hundred's of mW to several ten's of Watts of infrared power and are used in illuminators emitting from a few Watts up to several hundred Watts.

In-situ formation of microstructures near live cells using spatially structured near-infrared laser microbeam

Paper 7908-17 of Conference 7908
Date: Wednesday, 26 January 2011
Time: 4:40 PM ?5:00 PM

Author(s): Ninad D. Ingle, Ling Gu, Samarendra K. Mohanty, The Univ. of Texas at Arlington (United States)
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Cellular and axonal migration is important from various physiological aspects including immune-response, neuronal injury-repair and formation of functional cellular-networks during organogenesis. In order to study cellular behavior such as polarization in response to inhibition, physical obstacles have been created by different microfabrication methods. We report formation of linear microstructures from the culture media in regular petridish near growing cells using spatially-structured near infrared (NIR) laser beam. This would enable study of response of cells/axons to the immediate physical hindrance provided by such structure formation and also eliminate the biocompatibility requirement posed on artificial microstructure materials. We will present these results and put forward our hypothesis behind the structure formation mechanism.

Some aspects of far infrared spectroscopy of explosive materials

Paper 7938-19 of Conference 7938
Date: Wednesday, 26 January 2011
Time: 6:00 PM

Author(s): Norbert Palka, Mieczyslaw Szustakowski, Tomasz Trzcinski, Military Univ. of Technology (Poland)
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This paper presents some potentially interesting aspects of spectroscopic measurements of explosive materials in Far-Infrared (Terahertz) range: preparation of the samples, influence of grain size of particles inside the sample, influence of covering by clothes and influence of phlegmatization of explosives - addition an agent to an explosive material to stabilize or desensitize it. Moreover, two commonly used techniques - Far Infrared Fourier Spectroscopy and Time Domain Spectroscopy are presented and compared.

Higher operating temperature infrared detectors using quantum dots and type II superlattices

Paper 7951-3 of Conference 7951
Date: Thursday, 27 January 2011
Time: 8:50 AM ?9:20 AM

Author(s): Sanjay Krishna, Ctr. for High Technology Materials (United States)
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The third generation of infrared detectors has been focused on obtaining higher operating temperature (HOT) detectors. Even as the detector community has been trying to push the operating temperature higher, the refrigerator community has been undertaking research on developing low cost, light weight coolers. We have been undertaking research on infrared detectors based on InAs/GaAs quantum dots in a well (DWELL) and InAs/GaSb superlattices. We will discuss approaches to incorporate unipolar barriers in the superlattices to prevent noise generating mechanisms. We are also undertaking shape engineering of the dots to produce infrared detectors operating at higher temperatures.

Compact laser transmitter providing precision aligned visible and infrared beams

Paper 7923-13 of Conference 7923
Date: Thursday, 27 January 2011
Time: 9:00 AM ?9:20 AM

Author(s): Hong-Shik Lee, Yeo-Taek Yoon, Chang-Hyun Park, Haeng-In Kim, Kwangwoon Univ. (Korea, Republic of); Seung-Chan Lim, Korea Telecom (Korea, Republic of); Sang-Shin Lee, Kwangwoon Univ. (Korea, Republic of)
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The free space optics has received enormous attention in view of its variosu applications such as the visible light communications and especially the multiple integrated laser engagement systems (MILES). We have proposed and built a laser transmitter providing precision aligned visible and infrared beams, exploiting an optical sub-assembly module. Both visible (~650 nm) and infrared (~904 nm) laser diodes were combined by a wavelength division multiplexing filter and coupled to a short fiber. They were subsequentl collimated simultaneously to provide two collinear beams. The alignment angle between the visible and infrared beam was <0.01o; the propagation characteristics of the visible and infrared beams were evaluated.

Mid-infrared femtosecond frequency combs for sensing and optical clocks

Paper 7917-45 of Conference 7917
Date: Thursday, 27 January 2011
Time: 9:20 AM ?9:50 AM

Author(s): Irina T. Sorokina, Norwegian Univ. of Science and Technology (Norway); Evgeni Sorokin, Vienna Univ. of Technology (Austria)
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We review recent advances in frequency comb sources based on Cr2+:chalcogenide lasers, operating between 1.9 and 3.6 micron, and their applications to "frequency comb spectroscopy" and other sensing techniques. These lasers exhibit the broadest among existing lasers continuous tuning over 1400 nm and 80-fs pulses, all at ambient conditions. The lasers operate in transportable hybrid fiber-bulk form, and allow novel techniques like dual-comb method and intracavity spectroscopy. The femtosecond frequency combs also serve as a starting point for synchroniously pumped OPOs. The talk highlights the radical efficiency increase when such sources are applied to high-resolution molecular spectroscopy and gas sensing.

Mid-infrared photonics in silicon

Paper 7917-46 of Conference 7917
Date: Thursday, 27 January 2011
Time: 10:30 AM ?11:00 AM

Author(s): Alexander Spott, Yang Liu, Tom W. Baehr-Jones, Rob Ilic, Michael Hochberg, Univ. of Washington (United States)
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Silicon waveguides have, to date, largely been designed to operate near the telecommunication bands in the near infrared. The mid-infrared (MIR) wavelengths, which range from two to twenty microns, are critical for a number of application areas, including chemical bond spectroscopy and thermal imaging. We show results, using commercially available silicon-on-sapphire wafers, for low-loss (~4 dB/cm) waveguides and what we believe to be the first working microresonators operating at wavelengths around 5.5 um in silicon guides. This talk will discuss the applications for mid-infrared integrated photonics in the silicon system, particularly for sensing and nonlinear optics.

Nanoprocessing of glass and PMMA by means of near infrared sub-15 femtosecond laser pulses

Paper 7921-19 of Conference 7921
Date: Thursday, 27 January 2011
Time: 11:00 AM ?11:20 AM

Author(s): Huijing Zhang, Karsten König, Maziar Afshar, Dara Feili, Helmut Seidel, Univ. des Saarlandes (Germany)
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A near infrared sub-15 femtosecond laser scanning microscope was employed for structuring of colored glass and PMMA. The 400 mW Ti-Sapphire laser works at 85 MHz with an M-shaped emission spectrum with maxima at 770 nm and 827 nm. By using a high NA objective, light intensity of about 10 TW/cm² at the focal plane can be reached. A mean power of less than 17 mW, which corresponds to the pulse energy of 0.2 nJ, was sufficient for drilling holes and ablating materials. Two-photon fluorescence measurements, which can be performed with the same microscope, reveal the creation of filaments within the specimens, likely caused by self focusing effects. Holes with a diameter of less than 170 nm, were produced without chemical etching. The results are compared with those obtained by using 300 fs and 3 ps laser pulses.

Field assisted sintering of infrared sensor windows

Paper 7912-65 of Conference 7912
Date: Thursday, 27 January 2011
Time: 11:30 AM ?11:50 AM

Author(s): Aaron Rape, Joginder Singh, Applied Research Lab. (United States); Sudhir B. Trivedi, Brimrose Corp. of America (United States); Vijay Shukla, Rajendra Sadangi, Plasmadynamics, LLC (United States); Narasimha S. Prasad, NASA Langley Research Ctr. (United States)
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Several materials including MgAl2O4 (Spinel) and Lutetium Oxide (Lu2O3) are good candidate materials for IR window applications. Effort is underway to produce nano-grained polycrystalline transparent materials that will be fabricated by the emerging Field Assisted Sintering Technology (FAST). FAST allows sintering of ceramic materials close to 100% theoretical density to achieve high IR transparency. Several material systems will be sintered using the FAST system. FAST parameters will be studied and optimized to achieve fully dense samples of these materials. Optical and micro-structural properties of these IR ceramic windows materials will be characterized and described in this paper.

Infrared spoof plasmons on nano-membranes: physics and applications

Paper 7946-59 of Conference 7946
Date: Thursday, 27 January 2011
Time: 2:00 PM ?2:30 PM

Author(s): Gennady Shvets, The Univ. of Texas at Austin (United States); Alexander Khanikaev, The Univ. of Texas at Austin (United States) and Macquarie Univ. (Australia); S. Hossein Mousavi, Burton Neuner III, The Univ. of Texas at Austin (United States)
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Highly confined ``spoof'' surface plasmon-like (SSP) modes are theoretically predicted to exist in a perforated metal film coated with a thin dielectric layer. Strong confinement of the modes is achieved due to the additional waveguiding by the layer. Spectral characteristics, field distribution, and lifetime of these SSPs are tunable by the holes' shape and geometry. SSPs exist both above and below the light line, enabling two different classes of applications: to "perfect" far-field absorption and to efficient emission into guided modes. It is shown experimentally that these plasmon-like modes can turn thin weakly-absorbing semiconductor films into "perfect" absorbers.


Spectral beam combining of infrared quantum cascade laser arrays

Paper 7953-58 of Conference 7953
Date: Thursday, 27 January 2011
Time: 3:00 PM ?3:20 PM

Author(s): Ralf Ostendorf, Stefan Hugger, Rolf Aidam, Rainer Loesch, Quankui K. Yang, Wolfgang Bronner, Rachid Driad, Frank Fuchs, Joachim Wagner, Fraunhofer-Institut für Angewandte Festkörperphysik (Germany); Michael Raab, Eugen Romasew, Hans-Dieter Tholl, Diehl BGT Defence GmbH & Co. KG (Germany)
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We combined the output of electrically driven InP-based quantum cascade (QC) laser arrays by applying the concept of spectral beam combining in an external cavity (EC) setup. The EC setup provides wavelength selective feedback and forces each single emitter on the QC mini-bar to operate at a well defined wavelength. We demonstrate that spectral beam combining can be applied at different wavelengths in the mid- and far infrared region. Furthermore, the EC setup allows a certain degree of tunability of the central wavelength during operation by rotating the grating.

Double-cladding fiber-based detection system for intravascular mapping of fluorescent molecular probes

Paper 7894-22 of Conference 7894
Date: Saturday, 22 January 2011
Time: 4:40 PM ?5:00 PM

Author(s): R. Nika Razansky, Mathias S. Mueller, Nikolaos C. Deliolanis, Technische Univ. München (Germany); Farouc A. Jaffer M.D., Massachusetts General Hospital (United States); Alexander W. Koch, Vasilis Ntziachristos, Technische Univ. München (Germany)
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Early detection of high-risk coronary atherosclerosis remains an unmet clinical challenge. In this work we improve previously demonstrated near-infrared fluorescence catheter system performance by introducing a novel high resolution sensor. The main challenge of the intravascular sensor is to provide a highly focused spot at an application relevant distance on one hand and a highly efficient collection of emitted light on the other. The sensor automatically rotates and is being pulled-back, while each scanned point is mapped according to the amount of detected fluorescent emission. The resulting map of fluorescence activity in combination with artery morphology associates the atherosclerotic plaques with the inflammation process. This can help to differentiate the atherosclerotic plaques based on their biological activity and identify the ones that prone to rupture and require more medical attention.

Integrated plasmonic systems for ultrasensitive biodetection

Paper 7943-1 of Conference 7943
Date: Sunday, 23 January 2011
Time: 10:30 AM ?11:00 AM

Author(s): Hatice Altug, Ahmet A. Yanik, Ronen Adato, Serap Aksu, Alp Artar, Min Huang, Arif E. Cetin, Boston Univ. (United States)
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Plasmonics, by localizing light to the sub-wavelength volumes and dramatically enhancing local fields, is enabling myriad of exciting possibilities in bio-detection field. In this talk, I will demonstrate an ultra-sensitive surface-enhanced infrared spectroscopy enabling direct detection of molecular specific signatures of proteins from monolayer thick films. Our enhancement method exploits engineering of diffractive couplings among plasmonic nano-antenna arrays. I will then present a low-cost fabrication method for high-throughput fabrication of these engineered antenna arrays. Finally, I will show an integrated nanoplasmonic-nanofluidic sensor platform leading to targeted analyte delivery and dramatically improved sensor response time.

Intrinsic optical signal imaging of glucose-stimulated physiological responses in the insulin secreting INS-1 ß-cell line

Paper 7907-35 of Conference 7907
Date: Sunday, 23 January 2011
Time: 3:50 PM ?4:10 PM

Author(s): Yi-Chao Li, Wanxing Cui, Xujing Wang, Franklin Amthor, Xin-Cheng Yao, The Univ. of Alabama at Birmingham (United States)
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Intrinsic optical signal (IOS) imaging has been established for noninvasive monitoring of stimulus-evoked physiological responses in the retina and other neural tissues. Recently, we extended the IOS imaging technology for functional evaluation of an insulin secreting ß-cell line: the INS-1 cells. It is a popular model for investigating ß-cell function and diabetes. Our experiments indicate that IOS imaging allows simultaneous monitoring of glucose-stimulated physiological responses in multiple cells with high spatial (sub-cellular) and temporal (sub-second) resolution, and rapid image sequences reveal transient optical responses that have time courses comparable to the glucose-evoked ß-cell electrical activities.

Inverse problem for biomedical applications: use of prior information on target and forward model parameters

Paper 7896-21 of Conference 7896
Date: Monday, 24 January 2011
Time: 8:30 AM ?8:50 AM

Author(s): Fabrizio Martelli, Univ. degli Studi di Firenze (Italy); Samuele Del Bianco, Istituto di Fisica Applicata Nello Carrara (Italy); Giovanni Zaccanti, Univ. degli Studi di Firenze (Italy)
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We propose the use of a retrieval operator for biomedical applications in near-infrared spectroscopy. The proposed retrieval operator is based on the "Optimal Estimation" method. The main characteristic of this method relates to the possibility to include prior information both on target and on forward model parameters of the inversion procedure. Prior information determines a benefit for the whole retrieval procedure. The procedure has been tested on time-resolved simulated experiments obtained with a Monte Carlo code. The results obtained show that an improved performance of the procedure is obtained when prior information on target and forward model parameters is available.

High power optically pumped VECSELs emitting in 1310 nm and 1550 nm bands

Paper 7919-2 of Conference 7919
Date: Monday, 24 January 2011
Time: 8:45 AM ?9:15 AM

Author(s): Alexei Sirbu, Alexandru Mereuta, Andrei Caliman, Eli E. Kapon, Ecole Polytechnique Fédérale de Lausanne (Switzerland); Jussi Rautiainen, Jari Lyytikainen, Oleg Okhotnikov, Tampere Univ. of Technology (Finland); Jaroslaw Walczak, Tomasz Czyszanowski, Technical Univ. of Lodz (Poland)
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Optically pumped VECSELs emitting in 1310 nm and 1550 nm bands based on wafer fused InAlGaAs/InP-AlGaAs/GaAs gain mirrors with 3 and 5 groups of quantum wells in active half-cavities that are bonded to intra-cavity diamond heat-spreaders demonstrate very low thermal impedance of 2 K/W, high CW single mode continuous wave output of 2 W at room temperature for devices with 5 groups of quantum wells and more than 4 W for devices with 3 groups of quantum wells. Thermal and optical modelling of these devices is performed resulting in quite good agreement with experimental results.

A CARS solution with high temporal resolution

Paper 7903-44 of Conference 7903
Date: Monday, 24 January 2011
Time: 3:41 PM ?3:53 PM

Author(s): Stefanie Landwehr, William Hay, Vishnu Vardhan Krishnamachari, Leica Microsystems CMS GmbH (Germany)
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Confocal and multiphoton microscopy are powerful fluorescence techniques for morphological and dynamics studies of labeled elements. For non-fluorescent components, CARS (Coherent Anti-Stokes Raman Scattering) microscopy can be used for imaging various elements of cells such as lipids, proteins, DNA, etc. This technique is based on the intrinsic vibrational properties of the molecules. Leica Microsystems has combined CARS technology with its TCS SP5 II confocal microscope to provide several advantages for CARS imaging. The Leica TCS CARS combines two technologies in one system: a conventional scanner for maximum resolution and a resonant scanner for highly time resolved imaging. For CARS microscopy, two picosecond near-infrared lasers are tightly overlapped spatially and temporally and sent directly into the confocal system. The conventional scanner can be used for morphological studies and the resonant scanner for following dynamic processes of unstained living cells. The fast scanner has several advantages over other solutions. First, the sectioning is truly confocal and does not suffer from spatial leakage. Second, the high speed (29 images/sec @ 512x512 pixels) provides fast data acquisition at video rates, allowing studies at the sub-cellular level. In summary, CARS microscopy combined with the tandem scanner makes the Leica TCS CARS a powerful tool for multi-modal and three-dimensional imaging of chemical and biological samples. We will present our solution and show results from recent studies with the Leica CARS instrument to illustrate the high flexibility of our system.

Out-of-plane translatory mems actuator with extraordinary large stroke for optical path length modulation

Paper 7930-15 of Conference 7930
Date: Tuesday, 25 January 2011
Time: 1:50 PM ?2:10 PM

Author(s): Thilo Sandner, Thomas Grasshoff, Harald Schenk, Fraunhofer Institute for Photonic Microsystems (Germany); Andreas Kenda, Carinthian Tech Research AG (Austria)
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A translatory MOEMS actuator with extraordinary large stroke - especially developed for fast optical path length modulation in miniaturized FTIR-spectrometers - is presen瑃ed. A precise translational out-of-plane oscillation at 500 Hz with large stroke of up to 1 mm is realized by means of a new suspension design of the comparative large mirror plate with 19.6 mm² aperture using four pantographs. The MOEMS device is driven electro- statically resonant and is manufactured in a CMOS compatible SOI process. Up to ?500 祄 amplitude has been measured in vacuum of 50 Pa and 90 V driving voltage.

Pixel isolation of low dark-current large-format InAs/GaSb superlattice complementary barrier infrared detector focal plane arrays with high fill factor

Paper 7945-67 of Conference 7945
Date: Tuesday, 25 January 2011
Time: 4:45 PM ?5:00 PM

Author(s): Jean Nguyen, Cory J. Hill, Don Rafol, Sam A. Keo, Alexander Soibel, David Z. Y. Ting, Jason M. Mumolo, John K. Liu, Sarath D. Gunapala, Jet Propulsion Lab. (United States)
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Low dark current and high fill factor are two crucial characteristics for the realization of the InAs/GaSb superlattice technology as third generation FPAs. Recent development proved high performance results for CBIRD design, and a high-quality etch technique is required to minimize surface leakage currents. We report on a n-CBIRD with 10.3 um cutoff, exhibiting a responsivity of 1.7 A/W and dark current density of 1x10^-5 A/cm2 at 77K under 0.2 V bias, without AR coating and without passivation. Results from four different mesa isolation techniques are compared on single element diodes. Our technique yielded more than 2.5 times improvement in dark current density and near-vertical sidewalls. Using this etching technique, we implement a 1k x 1k p-CBIRD array with 11 um cutoff. Operating at 80K, the array yielded a 81% fill factor with 98% operability and performance results of 21% quantum efficiency, 53 mK NEDT, and NEI of 6.9x10^13 photons/sec-cm2.

Functional imaging of tumor-associated lymphatics

Paper 7910-39 of Conference 7910
Date: Tuesday, 25 January 2011
Time: 6:20 PM ?6:40 PM

Author(s): Sunkuk Kwon, Eva M. Sevick-Muraca, The Univ. of Texas Health Science Ctr. at Houston (United States)
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Abnormal lymphatic function and flow are implicated in a number of pathological conditions, including cancer metastasis. Yet despite the important role of lymphatics as a critical pathway for cancer metastasis, relatively little is known about tumor-associated lymphatic function, due in part to the inability to directly image the lymphatics in vivo. Herein, we developed an approach to non-invasively and quantitatively image transient changes of lymphatic contractile function and flow patterns in response to tumor progression and metastasis using a near-infrared (NIR) fluorescence imaging technique.

NIR DLP?hyperspectral imaging system for medical applications

Paper 7932-3 of Conference 7932
Date: Wednesday, 26 January 2011
Time: 9:00 AM ?9:20 AM

Author(s): Eleanor F. Wehner, Abhas Thapa, The Univ. of Texas at Arlington (United States); Edward Livingston, The Univ. of Texas Southwestern Medical Ctr. at Dallas (United States); Karel J. Zuzak, The Univ. of Texas at Arlington (United States) and Digital Light Innovations (United States)
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Hyperspectral reflectance imaging has been extended beyond the visible into the near infrared (NIR) spectral range. A novel NIR DLP?based system has been developed and tested to produce chemically encoded images for clinical utility. NIR illumination penetrates into deeper tissue and detects reflectance spectroscopy from areas previously inaccessible. The new NIR system can image anteriorly placed anatomical structures usually obscured by connective tissues, which can be used to assist surgeons during gall bladder surgery.

Dual-modality in-vivo imaging for MRI detection of tumors and NIRF-guided surgery using multicomponent nanoparticles

Paper 7908-4 of Conference 7908
Date: Wednesday, 26 January 2011
Time: 9:10 AM ?9:30 AM

Author(s): Jaehong Key, Purdue Univ. (United States); Kwangmeyung Kim, Ick Chan Kwon, Kuiwon Choi, Korea Institute of Science and Technology (Korea, Republic of); Deborah Knapp, James F. Leary, Purdue Univ. (United States)
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Detecting early-stage cancer noninvasively and removing it specifically during surgery is challenging. Magnetic resonance imaging (MRI) is excellent for noninvasive cancer detection, but MRI using contrast agents does not have enough sensitivity to delineate tumor margins during surgery, and is too slow for real-time, guided-surgery. NIRF imaging can be used to delineate tumor margins during surgery, where intervening tissue is resected or removed. To overcome these restrictions we have developed dual-modality in-vivo imaging for MRI detection of tumors and NIRF-guided surgery using multi-component nanoparticles with NIRF dye, Cy5.5, conjugated to superparamagnetic iron oxide (SPIO) embedded glycol chitosan (HGC) nanoparticles.

Effect of the oxide-semiconductor interface on the passivation of hybrid type-II superlattice long-wave infrared photodiodes

Paper 7945-72 of Conference 7945
Date: Wednesday, 26 January 2011
Time: 9:40 AM ?9:55 AM

Author(s): Jill A. Nolde, U.S. Naval Research Lab. (United States); Rory Stine, Nova Research, Inc. (United States); Eric M. Jackson, Chadwick L. Canedy, Igor Vurgaftman, U.S. Naval Research Lab. (United States); Serguei I. Maximenko, Global Defense Technology & Systems, Inc. (United States); Chaffra A. Affouda, U.S. Naval Research Lab. (United States); Maria Gonzalez, Global Defense Technology & Systems, Inc. (United States); Edward H. Aifer, Jerry R. Meyer, U.S. Naval Research Lab. (United States)
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In order to be commercially viable, type-II superlattice (T2SL) LWIR focal plane array technology requires the development of effective passivation of exposed surfaces. Here we investigate the relationship between the thickness and composition of the native oxide at the T2SL-SiO2 interface and diode performance. Sidewall resistivity is compared between samples with untreated surfaces, with the native oxide chemically etched, and with ozone exposure to promote oxide growth. Identically processed InAs- and GaSb-capped pieces were studied using X-ray photoelectron spectroscopy to determine the composition and thickness of the surface oxides which is then correlated to device performance.

Room-temperature 4.0-祄 broadened optical pumping injection cavity lasers

Paper 7953-39 of Conference 7953
Date: Wednesday, 26 January 2011
Time: 2:40 PM ?3:00 PM

Author(s): Linda J. Olafsen, Lauren E. Bain, Baylor Univ. (United States); William W. Bewley, Igor Vurgaftman, Jerry R. Meyer, U.S. Naval Research Lab. (United States); Hao Lee, Sarnoff Corp. (United States) and Applied Optoelectronics Inc. (United States); Ramon U. Martinelli, Sarnoff Corp. (United States)
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Broadened optical pumping injection cavity (OPIC) lasers pumped at fixed (1850 nm) and resonantly tuned optical pumping wavelengths operate in pulsed mode above room temperature. These devices employ InAs/GaSb/InAs/AlSb type-II W active regions positioned in resonant cavities between GaSb/AlAsSb mirror stacks. Emission wavelengths range from 3.59 祄 at 78 K to 4.01 祄 at 310 K for 1850 nm pumping. The broadened OPIC configuration presents a distinct advantage over earlier reported OPIC devices as the broader resonance leads to efficient emission across a wide temperature range for a single pump wavelength (1850 nm), providing over 400 nm of wavelength tuning.

Cr:ZnSe planar waveguide mid-IR laser

Paper 7912-54 of Conference 7912
Date: Wednesday, 26 January 2011
Time: 4:40 PM ?5:00 PM

Author(s): Jonathan E. Willimas, Dmitri V. Martyshkin, Vladimir V. Fedorov, The Univ. of Alabama at Birmingham (United States); Igor S. Moskalev, IPG Photonics - Mid-Infrared Lasers (United States); Renato P. Camata, Sergey B. Mirov, The Univ. of Alabama at Birmingham (United States)
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We report the first mid-IR Cr:ZnSe planar waveguides lasing and application of the Cr:ZnSe thin-film structures for passive Q-switching of the solid state lasers. The lasing of the Cr:ZnSe waveguide was achieved at 2.6 祄 under optical pulse excitation at 1.56 祄. The laser threshold was equal to 100 mJ/cm^2. Highly doped Cr:ZnSe/sapphire sample was used for passive Q-switching of the fiber pumped Er(0.5%):YAG laser operating at 1645 nm. Passively Q-switched Er:YAG laser operated at repetition rate of 20 kHz with an output power of 100 mW and the ratio of the Q-switched to free-running output power of 67%.

VLWIR high operating temperature non-equilibrium photovoltaic HgCdTe devices

Paper 7945-59 of Conference 7945
Date: Tuesday, 25 January 2011
Time: 1:50 PM ?2:10 PM

Author(s): Silviu Velicu, Christoph H. Grein, EPIR Technologies, Inc. (United States); Anne Itsuno, Jamie D. Phillips, Univ. of Michigan (United States)
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A nearly universal goal for infrared photon detection systems is to increase their operating temperature without sacrificing performance. Device designs have been proposed to suppress Auger processes in the absorber by placing it between exclusion and extraction junctions under reverse bias. In this work, we analyze the non-equilibrium operation of mid-wavelength infrared (MWIR), long wavelength infrared (LWIR) and very long wavelength infrared (VLWIR) HgCdTe devices and identify the performance improvements (operation temperature, responsivity, detectivity) expected when Auger suppression occurs. We will also describe our experimental work to realize the non-equilibrium structure and device requirements, with an emphasis on the molecular beam epitaxy growth of MWIR, LWIR and VLWIR structures. We will present an analysis and comparison of our theoretical and experimental non-equilibrium device results.

Mid-IR lasing of Cr:ZnSe/As2S3:As2Se3 composite materials

Paper 7912-55 of Conference 7912
Date: Wednesday, 26 January 2011
Time: 5:00 PM ?5:20 PM

Author(s): Dmitri V. Martyshkin, Vladimir V. Fedorov, The Univ. of Alabama at Birmingham (United States) and IPG Photonics Corp. (United States); Jonathan T. Goldstein, Air Force Research Lab. (United States); Sergey B. Mirov, The Univ. of Alabama at Birmingham (United States) and IPG Photonics - Mid-Infrared Lasers (United States)
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The proposed transition metal doped Cr:ZnSe/As2S3:As2Se3 composite materials with index matching of II-VI and V-VI components represent a new way for design of mid-infrared laser active fibers. It allows combining chalcogenide glasses as a host mid-IR fiber material with chromium doped II-VI semiconductor compounds which proved to be excellent mid-IR gain material. Chalcogenide glasses capability to vary refractive index from n=2.1 to n=2.5 provides a pathway to refractive index optimization and matching to ZnS (n=2.26) and ZnSe (n=2.44) crystals eliminating scattering losses. We report the first to our knowledge room-temperature laser oscillation of Cr: ZnSe/As2S3:As2Se3 compound at 2.4 祄.

The operation of nanoscale antennae with complex geometries

Paper 7937-46 of Conference 7937
Date: Tuesday, 25 January 2011
Time: 3:10 PM ?3:25 PM

Author(s): Matthew S. Sederberg, Abdulhakem Y. Elezzabi, Univ. of Alberta (Canada)
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The nanometer dimensions which allow for plasmonic resonsances in the optical regime also permit high spatial resolution and a compact antenna footprint. While scaling the antenna to larger dimensions allows for operating wavelengths in the mid-infrared, integration densities are drastically reduced. In order to increase integration densities, it would be desirable to design a nanoscale antenna which resonates in the mid-infrared. In this work, we investigate several antenna designs which incorporate complex geometry and demonstrate how it is possible to shift the operating wavelength of the antenna to the mid-infrared while maintaining a footprint which is comparable to their optical counterparts.

From multi kW continuous wave to multi MW femtosecond pulses: recent developments exploiting disk laser technology

Paper 7912-8 of Conference 7912
Date: Monday, 24 January 2011
Time: 8:50 AM ?9:10 AM

Author(s): Sascha Weiler, Marco Holzer, TRUMPF Laser- und Systemtechnik GmbH (Germany)
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Disk lasers combine high efficiency, excellent beam quality, high average and/or peak power with moderate cost and high reliability at multiple wavelengths, ranging from the infrared over the green to the ultraviolet. The demonstrated infrared average powers range from tens of kW in CW operation over >1 kW in ns pulses to >100 W in ps pulses and > 70 W in fs pulses. Wavelength conversion for nearly all modes of operation, e.g. 700 W@515nm in ns pulses, enlarges the fields of applications, making the disk technology today's most versatile laser platform.

Quantum cascade laser-based replacement for FTIR microscopy

Paper 7902-45 of Conference 7902
Date: Monday, 24 January 2011
Time: 12:20 PM ?12:40 PM

Author(s): Miles Weida, Brandon Yee, Daylight Solutions, Inc. (United States)
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External cavity quantum cascade (QC) lasers provide a broadly tunable mid-infrared (IR) light source that has potential to be coupled with room temperature microbolometer focal plane arrays to realize low-cost, compact, room temperature IR microscopes that surpass the performance of Fourier transform infrared (FTIR) microscopes, and are suitable for tissue analysis in clinical environments. The present study considers the issues of constructing an external cavity QC laser-based IR microscope, and offers demonstration of key performance parameters.

In-vitro photothernmal destruction of cancer cells using gold nanorods and pulsed-train near-infrared lasers

Paper 7909-6 of Conference 7909
Date: Saturday, 22 January 2011
Time: 10:40 AM ?11:00 AM

Author(s): Jui-Teng Lin, National Taiwan Univ. (Taiwan); Yueh-Sheng Chiang, Hsia-Wei Liu, Fu-Jen Catholic Univ. (Taiwan); Guan-Hung Lin, Hsinyu Lee, Wen-Ming Hsu, National Taiwan Univ. (Taiwan)
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We present a novel pulsed-train laser system (with wavelength at 750, 808 and 915 nm) with real time temperature monitoring of the laser heated cancer cell solutions at various absorption coefficients (A). The irradiation time needed (t) for killing the cancel cells 30-90 seconds is much shorter than conventional methods (5-10 minutes). Cell viabilities in gold nanorods mixed and controlled solutions are studied by green fluorescence. We also study the selective features of various antibody conjugations expressed on the surface of various cancer cells. Dynamic temperature profiles of the laser-heated cell solutions various laser fluence are recorded and compared with theoretical simulations.

'Spectral a priori' to 'spatial a posteriori' in continuous-wave image reconstruction in near-infrared optical tomography

Paper 7892-12 of Conference 7892
Date: Saturday, 22 January 2011
Time: 2:00 PM ?2:20 PM

Author(s): Guan Xu, Daqing Piao, Oklahoma State Univ. (United States); Hamid Dehghani, The Univ. of Birmingham (United Kingdom)
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This work examines the robustness of spectral prior to continuous-wave based image reconstruction for unique recovering of chromophores and scattering property distributions by analytical approaches and simulation. The findings include: 1) the analytical solution shows that the unknown parameters can be independently reconstructed with continuous-wave measurements; 2) the level of artifacts in scattering power reconstruction is intrinsically most significant; 3) the DC only reconstruction produces least background artifacts, and; 4) increasing the number of wavelengths does not necessarily improve the reconstruction accuracy; 5) including DC component in frequency-domain improves reconstruction outcome more than neglecting DC.

Course: Modern Optical Testing

Date: Sunday, 23 January 2011
Time: 8:30 AM ?12:30 PM

Instructor(s): James C. Wyant, The Univ. of Arizona (United States)
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This course describes the basic interferometry techniques used in the evaluation of optical components and optical systems. It discusses interferogram interpretation, computer analysis, and phase-shifting interferometry, as well as various commonly used wavefront-measuring interferometers. The instructor describes specialized techniques such as testing windows and prisms in transmission, 90-degree prisms and corner cubes, measuring index inhomogeneity, and radius of curvature. Testing cylindrical and aspheric surfaces, determining the absolute shape of flats and spheres, and the use of infrared interferometers for testing ground surfaces are also discussed. The course also covers state-of-the-art direct phase measurement interferometers.

Study on the early diagnosis of Alzheimer's disease with near-infrared spectroscopy based on three-dimensional Monte Carlo modeling

Paper 7883E-114 of Conference 7883E
Date: Sunday, 23 January 2011
Time: 9:00 AM ?9:20 AM

Author(s): Ching-Cheng Chuang, National Taiwan Univ. (Taiwan); Chia-Wei Sun, National Yang-Ming Univ. (Taiwan); Chung-Ming Chen, National Taiwan Univ. (Taiwan); Chun-Yang Wang, Yao-Sheng Hsieh, National Chiao Tung Univ. (Taiwan)
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Brain atrophy is concomitant with Alzheimer's disease and other degenerative dementias, therefore, the difference of optical properties between normal subjects and patients, who with brain atrophy such as dementia and Alzheimer's disease, can indicate the status of brain structure. In our study, the photon migration in human brain of the normal, elderly and Alzheimer's subjects with various source-detector separations are analyzed based on three-dimensional Monte Carlo simulation. The three-dimensional brain model consists of scalp, skull, CSF layer, gray matter, and white matter from in vivo MRI image. The backscattered diffuse photons from each layer in brain are recorded by marking the deepest layer for brain status analysis. The expanded CSF layer affects the behavior of photon migration as waveguide effect thus the detected light distribution on brain surface implies the significant difference between normal and Alzheimer's subjects.

Near-infrared scattering imaging of depolarization waves in a rat hypoxic brain model and its application to assessment of brain tissue reversibility

Paper 7907-22 of Conference 7907
Date: Sunday, 23 January 2011
Time: 9:10 AM ?9:30 AM

Author(s): Satoko Kawauchi, Shunichi Sato, Yoichi Uozumi, Hiroshi Nawashiro, Miya Ishihara M.D., Makoto Kikuchi M.D., National Defense Medical College (Japan)
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We performed near-infrared scattering imaging of rat brain during hypoxia followed by reoxygenation to examine the relationship between spatiotemporal scattering change due to anoxic depolarization and tissue reversibility. About 2 min after starting hypoxia, scattering wave was generated focally in the bilateral outermost regions in the cortex and spread toward the midline. When reoxygenation was started before the scattering wave reached the middle point of the hemisphere, the tissue was reversible. When scattering wave further spread, reoxygenation did not save the brain. These results suggest that the coverage of scattering wave determines the brain tissue reversibility after hypoxia.

 

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