Del Mar Photonics

ACS Spring 2008 meeting - Femtosecond presentations for attention of Del Mar Photonics team members attending ACS meeting

Product news and updates - Training Workshops - Featured Customer - Other News

Del Mar Photonics is your one stop source for ultrafast (femtosecond) as well as continuum wave (CW) narrow linewidth Ti:Sapphire lasers Trestles LH Ti:Sapphire laser
Trestles LH is a new series of high quality femtosecond Ti:Sapphire lasers for applications in scientific research, biological imaging, life sciences and precision material processing. Trestles LH includes integrated sealed, turn-key, cost-effective, diode-pumped solid-state (DPSS). Trestles LH lasers offer the most attractive pricing on the market combined with excellent performance and reliability. DPSS LH is a state-of-the-art laser designed for today抯 applications. It combines superb performance and tremendous value for today抯 market and has numerous advantages over all other DPSS lasers suitable for Ti:Sapphire pumping. Trestles LH can be customized to fit customer requirements and budget.

Reserve a spot in our Femtosecond lasers training workshop in San Diego, California. Come to learn how to build a femtosecond laser from a kit
 

DPSS DMPLH lasers
DPSS DMP LH series lasers will pump your Ti:Sapphire laser. There are LH series lasers installed all over the world pumping all makes & models of oscillator. Anywhere from CEP-stabilized femtosecond Ti:Sapphire oscillators to ultra-narrow-linewidth CW Ti:Sapphire oscillators. With up to 10 Watts CW average power at 532nm in a TEMoo spatial mode, LH series lasers has quickly proven itself as the perfect DPSS pump laser for all types of Ti:Sapphire or dye laser.
Ideal for pumping of:

Trestles LH Ti:Sapphire laser
T&D-scan laser spectrometer based on narrow line CW Ti:Sapphire laser
 

New laser spectrometer OB' for research studies demanding fine resolution and high spectral density of radiation within UV-VIS-NIR spectral domains New laser spectrometer T&D-scan for research  that demands high resolution and high spectral density in UV-VIS-NIR spectral domains - now available with new pump option!
The T&D-scan includes a CW ultra-wide-tunable narrow-line laser, high-precision wavelength meter, an electronic control unit driven through USB interface as well as a software package. Novel advanced design of the fundamental laser component implements efficient intra-cavity frequency doubling as well as provides a state-of-the-art combined ultra-wide-tunable Ti:Sapphire & Dye laser capable of covering together a super-broad spectral range between 275 and 1100 nm. Wavelength selection components as well as the position of the non-linear crystal are precisely tuned by a closed-loop control system, which incorporates highly accurate wavelength meter.

Reserve a spot in our CW lasers training workshop in San Diego, California. Come to learn how to build a CW Ti:Sapphire laser from a kit
 

AOTF Infrared Spectrometer
Del Mar Photonics offer a handheld infrared spectrometer based on the acousto-optic tunable filter (AOTF). This instrument is about the size and weight of a video camera, and can be battery operated. This unique, patented device is all solid-state with no moving parts. It has been sold for a wide variety of applications such as liquid fuel analysis, pharmaceutical analysis, gas monitoring and plastic analysis. Miniature AOTF infrared spectrometer uses a crystal of tellurium dioxide to scan the wavelength. Light from a light source enters the crystal, and is diffracted into specific wavelengths. These wavelengths are determined by the frequency of the electrical input to the crystal. Since there are no moving parts, the wavelength scanning can be extremely fast. In addition, specific wavelengths can be chosen by software according to the required algorithm, and therefore can be modified without changing the hardware. After the infrared radiation reflects off of the sample, it is converted into an electrical signal by the detector and analyzed by the computer. Del Mar Photonics is looking for international distributors for RAVEN - AOTF IR spectrometer for plastic identification and for variety of scientific and industrial collaborations to explore futher commercial potential of AOTF technology.
 

Open Microchannel Plate Detector MCP-MA25/2

Open Microchannel Plate Detector MCP-MA25/2 - now in stock!
Microchannel Plate Detectors MCP-MA series are an open MCP detectors with one or more microchannel plates and a single metal anode. They are intended for time-resolved detection and make use of high-speed response properties of the MCPs. MCP-MA detectors are designed for photons and particles detection in vacuum chambers or in the space. MCP-MA detectors are used in a variety of applications including UV, VUV and EUV spectroscopy, atomic and molecular physics, TOF mass杝pectrometry of clusters and biomolecules, surface studies and space research.
MCP-MA detectors supplied as a totally assembled unit that can be easily mounted on any support substrate or directly on a vacuum flange. They also can be supplied premounted on a standard ConFlat flanges. buy online - ask for research discount!

 

Hummingbird EMCCD camera Hummingbird EMCCD camera
The digital Hummingbird EMCCD camera combines high sensitivity, speed and high resolution.
It uses Texas Instruments' 1MegaPixel Frame Transfer Impactron device which provides QE up to 65%.
Hummingbird comes with a standard CameraLink output.
It is the smallest and most rugged 1MP EMCCD camera in the world.
It is ideally suited for any low imaging application such as hyperspectral imaging, X-ray imaging, Astronomy and low light surveillance.
It is small, lightweight, low power and is therefore the ideal camera for OEM and integrators.
buy online
Femtosecond Transient Absorption Measurements system Hatteras Hatteras-D femtosecond  transient absorption data acquisition system
Future nanostructures and biological nanosystems will take advantage not only of the small dimensions of the objects but of the specific way of interaction between nano-objects. The interactions of building blocks within these nanosystems will be studied and optimized on the femtosecond time scale - says Sergey Egorov, President and CEO of Del Mar Photonics, Inc. Thus we put a lot of our efforts and resources into the development of new Ultrafast Dynamics Tools such as our Femtosecond Transient Absorption Measurements system Hatteras. Whether you want to create a new photovoltaic system that will efficiently convert photon energy in charge separation, or build a molecular complex that will dump photon energy into local heat to kill cancer cells, or create a new fluorescent probe for FRET microscopy, understanding of internal dynamics on femtosecond time scale is utterly important and requires advanced measurement techniques.

Reserve a spot in our Ultrafast Dynamics Tools training workshop in San Diego, California.
 

Beacon Femtosecond Optically Gated Fluorescence Kinetic Measurement System - request a quote  - pdf
Beacon together with Trestles Ti:sapphire oscillator, second and third harmonic generators. Femtosecond optical gating (FOG) method gives best temporal resolution in light-induced fluorescence lifetime measurements. The resolution is determined by a temporal width of femtosecond optical gate pulse and doesn't depend on the detector response function. Sum frequency generation (also called upconversion) in nonlinear optical crystal is used as a gating method in the Beacon femtosecond fluorescence kinetic measurement system. We offer Beacon-DX for operation together with Ti: sapphire femtosecond oscillators and Beacon-DA for operation together with femtosecond amplified pulses.

Reserve a spot in our Ultrafast Dynamics Tools training workshop in San Diego, California.
 

Terahertz systems, set ups and components
New band pass and long pass THz optical filters based on porous silicon and metal mesh technologies.
Band pass filters with center wavelengths from 30 THz into GHz range and transmissions up to 80% or better. Standard designs
with clear aperture diameters from 12.5 to 37.5 mm.
Long pass filters with standard rejection edge wavelengths from 60 THz into GHz range. Maximum transmission up to 80% or
better, standard designs at 19.0 and 25.4 mm diameters.
Excellent thermal (from cryogenic to 600 K) and mechanical properties
THz products:
THz Spectrometer kit with Antenna
THz transmission setup
THz time domain spectrometer Pacifica fs1060pca
THz time domain spectrometer Pacifica fs780pca
THz detectors: Golay cell and LiTaO3 piroelectric detectors
PCA - Photoconductive Antenna as THz photomixer
Pacifica THz Time Domain Spectrometer - Trestles Pacifica
Holographic Fourier Transform Spectrometer for THz Region
Wedge TiSapphire Multipass Amplifier System - THz pulses generation
Terahertz Spectroscopic Radar Mobile System for Detection of Concealed Explosives
Band pass filters with center wavelengths from 30 THz into GHz range
Long pass filters with standard rejection edge wavelengths from 60 THz into GHz range
Generation of THz radiation using lithium niobate
Terahertz crystals (THz): ZnTe, GaP, LiNbO3 - Wedge ZnTe

iPCA - interdigital Photoconductive Antenna for terahertz waves
Large area broadband antenna with lens array and high emitter conversion efficiency
iPCA with LT-GaAs absorber, microlens array for laser excitation wavelengths
l £  850 nm, adjusted hyperhemispherical silicon lens with a high power conversion efficiency of 0.2 mW THz power / W optical power. The iPCA can be used also as large area THz detector. The two types iPCAp and iPCAs have the same active interdigital antenna area but different contact pad directions with respect to the electrical THz field.
Interdigital Photoconductive Antenna for terahertz waves generation using femtosecond Ti:Sapphire laser

THz books
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IntraStage easily transforms test data from disparate sources into web-based quality metrics and engineering intelligence you can use.

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 1. Femtosecond dynamic-absorption studies of intermolecular vibrational coherence in bacteriochlorophyll and Zn杙orphyrin charge-transfer dynamics Warren F. Beck, beck@chemistry.msu.edu, Kevin L. Dillman, Sanela Lampa-Pastirk, and Katherine R. Shelly. Department of Chemistry, Michigan State University ...
2. Pump-DFWM-spectroscopy on β-carotene with shaped femtosecond pulses Jurgen Hauer, Tiago Buckup, and Marcus Motzkus, motzkus@staff.uni-marburg.de. Fachbereich Chemie, Philipps-Universitat Marburg, Hans-Meerwein-Strasse, 35037 Marburg, Germany Coherent control aims at influencing photochemical ...
3. Femtosecond and picosecond X-ray spectroscopy in chemical dynamics research Christian Bressler, christian.bressler@epfl.ch, Laboratoire de Spectroscopie Ultrarapide, Ecole Polytechnique Federale de Lausanne, ISIC-BSP, CH-1015 Lausanne, Switzerland We will present our recent results on the ...
4. Controlling the ablation of materials with pairs of femtosecond laser pulses Robert J Gordon, rjgordon@uic.edu, Yongtao Cheng, Zhan Hu, Yaoming Liu, Ting Lu, Sima Singha, and Tana E. Witt. Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, IL 60607 We ...
5. Photoinduced and dark bimolecular reactions in aqueous solutions of ruthenium (II)-tris-(2,2'-bipyridine) upon high intensity femtosecond laser excitation Alexander N. Tarnovsky, atarnov@bgsu.edu, Department of Chemistry & Center for Photochemical Sciences, Bowling Green State University ...
6. Ultrafast dynamics in single-walled carbon nanotubes
... , (2) Department of Chemistry, University of North Carolina at Chapel Hill, Caudill and Kenan Laboratories, Chapel Hill, NC 27599-3290 We have used femtosecond transient absorption spectroscopy to examine the excited state dynamics of single-walled carbon nanotube (SWNT) bundles embedded in polymer matrices ...
7. Ultrafast magnetization dynamics in cobalt-doped iron oxide nanocrystals: Effect of varying exchange interaction
... Station, TX 77842 The dynamics of photo-induced magnetization in chemically synthesized Co-doped iron oxide nanocrystals were investigated by femtosecond Faraday rotation measurements. Through the controlled doping of Co, nanocrystal samples of varying Co content were prepared ranging from Fe 3O 4 to ...
8. Charge transfer induced proton-coupled electron transfer
... relaxation dynamics of a photoexcited hydrogen bound 4-hydroxy-4'-nitrobiphenyl and t-butylamine association complex have been followed using both femtosecond and nanosecond transient absorption spectroscopy. Upon photoexcitation, the biphenyl molecule undergoes an intramolecular transition that transfers ...
9. Ultrafast coherent plasmon dynamics of individual metal nanostructures
... of individual, clean and adsorbate covered gold nanotips. We use second-harmonic interferometric autocorrelation with sub-10 fs excitation. The femtosecond temporal response of the plasmon polariton is found to be sensitive with respect to the structural parameters of the tips in terms of apex radius ...
10. Photopolymerization of conductive metal nanoparticles
... using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Electron transfer from ligand to metal was confirmed by femtosecond transient absorption measurements. Ligand radical cation coupling caused the linking of the metal nanoparticles. Photopolymerization of BTSH functionalized ...
11. Ultrafast dynamics at the air/water interface investigated with time-resolved electronic sum-frequency generation (TR-ESFG) spectroscopy
... of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama, Japan We developed a new surface-selective time-resolved nonlinear spectroscopy, femtosecond time-resolved electronic sum-frequency generation (TR-ESFG) spectroscopy, to investigate ultrafast dynamics at liquid interfaces. Its advantage ...
12. Ultrafast dynamics in the MLCT excited states of Ru(II) and Os(II) coordination complexes
... complexes John M. Papanikolas, john_papanikolas@unc.edu, Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599 We have used femtosecond transient absorption spectroscopy to address the fundamental photophysics of metal-to-ligand charge-transfer (MLCT) excited states in both symmetric ...
13. Advances in structural analyses of complex molecules
... sources like the LCLS at Stanford in the next few years. Such x-ray beams will have much higher peak brightness (more than 10**10 and shorter pulses(femtosecond rather than picosecond regime) than currently available. Examples will be used to illustrate the potential of this new class of sources for ...
14. First-principles approach to the anharmonic vibrational properties of biomolecules
... Dynamics Laboratory, Institute of Chemistry, Chinese Academy of Sciences, No. 2 1st North St. Zhongguancun, Haidian District, Beijing, 100080, China Femtosecond two-dimensional infrared (2D IR) spectroscopy can be used to monitor structures and dynamics of molecules in condensed phases by mapping out ...
15. Elucidation of mechanism following adaptive control of complex molecules in solution
... . Department of Chemistry and Biochemistry, University of Colorado at Boulder, Campus Box 215, Boulder, CO 80309 The significance of adaptive femtosecond pulse shaping stems from the use of iterative learning which allows for the control and study of electronically, structurally, and reactively complex ...
16. Probing quasiparticle and electron correlations by coherent 2-D spectroscopy
... Li, and Rafal Oszwaldowski. Department of Chemistry, University of California, Irvine, 1102 Natural Sciences II, Irvine, CA 92697-2025 Sequences of femtosecond optical pulses are designed to generate signals that are induced by correlations among elementary excitations. Applications to Frenkel excitons ...
17. Optimal control of photoproducts
... 117200, Gainesville, FL 32611-7200. We investigate the coherent control of azobenzene's excited state population dynamics by adaptive pulse shaping. Femtosecond excitation pulses perturb a molecule's excited state dynamics modulating the process photochemical outcome. Combined with pulse shaping and ...
18. Ultrafast dynamics of electron transfer and solvation processes at ammonia and water ice/metal interfaces
... ultrafast dynamics of interfacial electron transfer are studied for ultrathin ice and ammonia layers adsorbed on Cu(111) and Ru(001) surfaces using femtosecond time- and angle resolved two-photon-photoemission (2PPE) spectroscopy. In this process, photo-injection of electrons from the metal into the ...
19. Ultrafast 1- and 2-D infrared studies of complex chemical reactions
... .edu, James F. Cahoon, jfcaho@berkeley.edu, and Jacob P. Schlegel. Department of Chemistry, University of California at Berkeley, Berkeley, CA 94720 Femtosecond infrared spectroscopy is a valuable experimental tool for investigating the details of complex chemical reactions in ambient solution. UV-pump ...
20. Watching the protein mambo: Spectroscopic probes of enzyme dynamics
... , samrat-dutta@uiowa.edu, and Amnon Kohen. Department of Chemistry, University of Iowa, Iowa City, IA 52242 The structural dynamics of enzymes at the femtosecond to picosecond time scale have been invoked to explain the results of temperature-dependent kinetic-isotope-effect measurements for a number ...
21. Nanoparticle induced light-harvesting membrane protein deformation (LH2) revealed by ultrafast spectroscopic study of the excitonic states
... Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Hai Dian Qu Zhong Guan Cun Nan San Jie 8 Hao, Beijing, 100080, China We used femto-second time resolved transient absorbance difference spectroscopy to investigate the membrane protein of a light-harvesting antenna complex (LH2 ...
22. Long-range proton transfer in aqueous acid-base reactions
... ,6-pyrenetrisulfonic acid (HPTS) and acetate in aqueous solution by probing the vibrational resonances of HPTS, acetate and the hydrated proton with femtosecond mid-infrared laser pulses. We find that PT in this model system takes place in a distribution of hydrogen-bound reaction complexes that differ ...
23. Taking it to the limit: Ultrafast dynamics of heat transport over ultrasmall distances
... and through molecules using an ultrafast heat bath. 1 The heat bath, a gold substrate, is flash-heated up to 1000 K in approximately 1 ps with a femtosecond laser pulse. A self-assembled monolayer, attached to the heat bath at one end by a Au-S bond, heats as thermal energy surges into the molecules ...
24. Ultrafast infrared spectroscopy of dilute HOD in aqueous salt solutions
... . The direct measurement of the dynamics of water molecules in the first solvation shells of Cl -, Br - and I - has been achieved recently by femtosecond midinfrared nonlinear spectroscopy. The previous approach of the electronic structure/molecular dynamics (ES/MD) method for calculating ultrafast vibrational ...
25. Simulations of coherent exciton dynamics in multidimensional spectroscopy
... based on the nonlinear exciton equations is presented for simulating and interpreting the response of chromophore aggregates to sequences of femtosecond laser pulses. Applications are made to the Fenna-Matthews-Olson (FMO) light harvesting complex. Some fundamental symmetries of multidimensional optical ...
26. Resolving the excited and ground state reaction coordinates in the green fluorescence protein and mutants with dispersed pump-dump probe spectroscopy
... -state photodynamics of wild-type (wt), S65T/H148D and S65T/H148E mutants of the Green Fluorescent Protein (GFP) system were characterized with femtosecond time-resolved dispersed multi-channel pump-dump-probe measurements. Discrete transient intermediates with specific spectral properties are identified ...
27. Hidden electronic excited state of enhanced green fluorescent protein (eGFP) by new multiplex two-photon absorption spectroscopy
... absorption (TPA) spectroscopy, which enables us to measure precise TPA spectra for a broad wavelength range, utilizing narrow-band and broad-band femtosecond pulses with multichannel detection. We applied this technique to study the electronic structure of enhanced green fluorescent protein (eGFP), ...
28. Infrared spectroscopy of tritiated water
... bond switching with correlation spectroscopy between the OD and OT stretching vibrations in H2O. We report on the infrared absorption spectrum and femtosecond infrared pump-probe spectroscopy of the OT stretching vibration of HOT in H2O. We compare IR absorption line shape parameters between the three ...
29. Multiple exciton generation in semiconductor quantum dots and applications to third generation solar photon conversion
... and hole relaxation, multiple exciton generation, cooling, charge transport, and interfacial charge transfer of the photogenerated carriers with femtosecond (fs) to ns time resolution. We have been studying these fundamental dynamics in various bulk and nanoscale semiconductors (quantum dots (QDs), ...
30. New insights into electronic structures of semiconductor nanocrystals through single-particle and ultrafast spectroscopies
... and ultrafast spectroscopic techniques. For example, we use single-nanocrystal photoluminescence (PL) excitation spectroscopy in conjunction with femtosecond time-resolved PL to study the structure of band-edge optical transitions and mechanism for intraband relaxation. Further, we apply single-nanocrystal ...
31. Charge transfer excitons on a crystalline organic semiconductor surface
... of these transient species. Here, we report the observation of CT excitons on the surface of a crystalline organic semiconductor, pentacene, from femtosecond time-resolved two-photon photoemission spectroscopy. In this model system, pentacene is the electron donor and vacuum is the 揺lectron acceptor ...
32. Atomic solvation dynamics and the breakdown of linear response
... -solvated (Na +:e ? ?a partially-atomic, solvent-supported tight-contact pair (TCP) ?created out of equilibrium through two well-defined pathways: femtosecond photodetachment of Na ? and photoinduced electron transfer/attachment to Na +. We find that the ultrafast time-resolved solvation of nascent ...
33. Infrared pump-probe investigation of melanin vibrational relaxations
... properties of melanin samples prepared using a variety of techniques. The melanin samples were characterized using FTIR and studied using femtosecond infrared pump-probe spectroscopy. The pump-probe results allow for comparison of the samples' efficiency at dissipating energy. These results will indicate ...
34. Photochemical investigations of diiron model complexes containing the [Fe2O(O2CR)2]2+ core
... modulate dioxygen reactivity in these iron centers. Various optical spectroroscopic methods (i.e., photoacoustic calorimetry, UV_Vis absorption and femtosecond transient absorption spectroscopy) were employed to characterize the electronic structure and excited state characteristics of these complexes ...
35. 1,2,3,4,5-Pentamethyl-cyclopentadiene dynamics probed by photoionization
... , the molecule has ample energy to form isomers. Our experiments show conclusively, however, that no measurable structural changes take place on a femtosecond or picosecond timescale. PHYS Poster Session - Optical Probes of Dynamics in Complex Environments 7:30 PM-10:00 PM, Wednesday, April 9 ...
36. Static and time resolved vibrational sum frequency spectroscopy studies of membrane bound water
... OD region at the membrane/water interface, using a variety of lipids and trace HOD in H 2O, and the latter by application of the newly developed femtosecond time resolved SFG to the same model membrane systems. Our results suggest that water chemical heterogeneity differs between lipids in a chemically ...
37. Investigating semiconductor-photosensitizers using N3 dye analogs
... and electrochemistry, will be reported. Initial studies concerning electron transfer dynamics of these dyes adsorbed onto TiO2 films using femtosecond infrared spectroscopy will also be described. These studies will examine the effects of adding alkyl bridges of increasing length on electron transfer ...
38. Electron transfer dynamics at the ZnO (10-10) surface
... in electron transfer across this surface and in electron transport in devices featuring ZnO photoanodes. Additionally, we observe ultrafast sub-20 femtosecond cooling of hot electrons within the ZnO conduction band, suggesting that hot carrier transport may not be feasible in this material. Interfacial ...
39. Effect of morphology in KNb6O17 nanosheets and nanoscrolls on photocatalytic H2 evolution from water
... /h (175 mg of catalyst). Similarities and differences in the two catalysts are discussed using data from TEM, HRTEM, UV/vis, fluorescence, IR, and femtosecond absorption spectroscopy. 2nd Symposium on Hydrogen from Renewable Sources and Refinery Applications 1:00 PM-5:00 PM, Sunday, April 6, 2008 ...

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1. 100%PHYS 352 - Ultrafast dynamics of intramolecular electron transfer in 2,7-dicyanospirobifluorene: Transient absorption anisotropy study
PHYS 352 Ultrafast dynamics of intramolecular electron transfer in 2,7-dicyanospirobifluorene: Transient absorption anisotropy study Artem Khvorostov, artemkh@andromeda.rutgers.edu and Piotr Piotrowiak, piotr@andromeda.rutgers.edu. Department of Chemistry, Rutgers, The State University of New Jersey ...
2. 99%PHYS 161 - Molecular structural dynamics studied by ultrafast optical and X-ray transient absorption spectroscopy
PHYS 161 Molecular structural dynamics studied by ultrafast optical and X-ray transient absorption spectroscopy Lin X. Chen, lchen@anl.gov 1, Xiaoyi Zhang 2, Erik C. Wasinger, wasinger@anl.gov 3, Di-Jia Liu, liud@cmt.anl.gov 4, Klaus Attenkofer 5, and Guy Jennings 5. (1) Chemistry, Argonne National ...
3. 99%PHYS 266 - Coherent, nonlinear, and ultrafast nanoplasmonics
PHYS 266 Coherent, nonlinear, and ultrafast nanoplasmonics Mark I. Stockman, mstockman@gsu.edu, Department of Physics and Astronomy, Georgia State University, Atlanta, FL 30303 This talk introduces and reviews new ideas and recent progress in coherent, nonlinear and ultrafast nanoplasmonics. It includes ...
4. 98%PHYS 253 - Ultrafast 2-D vibrational spectroscopy of molecular monolayers
PHYS 253 Ultrafast 2-D vibrational spectroscopy of molecular monolayers Jens Bredenbeck, bredenbeck@biophysik.org, Department of Physics, Johann Wolfgang Goethe-University, Max von Laue Strasse 1, 60438 Frankfurt/Main, Germany, Avishek Ghosh, ghosh@amolf.nl, Department of Femtophysics, FOM Institute ...
5. 98%COMP 41 - Ultrafast transformation of graphite to diamond: An ab initio study of graphite under shock compression
COMP 41 Ultrafast transformation of graphite to diamond: An ab initio study of graphite under shock compression Nir Goldman, goldman14@llnl.gov 1, Christopher J. Mundy, chris.mundy@pnl.gov 2, Evan J. Reed 1, I Feng W. Kuo, kuo2@llnl.gov 1, Laurence E. Fried, fried1@llnl.gov 3, and Alessandro Curioni ...
6. 98%PHYS 337 - Synthesis and ultrafast chelation dynamics of novel molecular photoswitches
PHYS 337 Synthesis and ultrafast chelation dynamics of novel molecular photoswitches Tung T. To, tung.to@nist.gov and Edwin J. Heilweil, edwin.heilweil@nist.gov. Physics Laboratory, Optical Technology Division, National Institute of Standards and Technology, 100 Bureau Drive Stop 8443, Gaithersburg ...
7. 98%PHYS 56 - Ultrafast optical studies of electronic relaxation across the interface in CdS/CdSe/CdS quantum-dot quantum-well heterostructures
PHYS 56 Ultrafast optical studies of electronic relaxation across the interface in CdS/CdSe/CdS quantum-dot quantum-well heterostructures Wei Qian 1, Alexander W. Schill 2, Christopher Gaddis, chris.gaddis@gmail.com 1, and Mostafa A. El-Sayed, mostafa.el-sayed@chemistry.gatech.edu 1. (1) Laser Dynamics ...
8. 98%PHYS 213 - Ultrafast response of semiconductor nanocrystals to high-photon energy absorption: Multiexcitons from a single photon
PHYS 213 Ultrafast response of semiconductor nanocrystals to high-photon energy absorption: Multiexcitons from a single photon Richard D. Schaller, rdsx@lanl.gov 1, Milan Sykora, sykoram@lanl.gov 2, Jeffrey M. Pietryga, pietryga@lanl.gov 1, and Victor I. Klimov 1. (1) Chemistry Division, Los Alamos ...
9. 98%PHYS 165 - Ultrafast vibrational dynamics of asymmetric hydrogen-bonded dimers
PHYS 165 Ultrafast vibrational dynamics of asymmetric hydrogen-bonded dimers Poul B. Petersen, poul@mit.edu, Sean T Roberts, seanr@mit.edu, Matthew W. Kanan, mkanan@mit.edu, Elizabeth R. Young, eyoung@mit.edu, Rebecca A. Nicodemus, nicodemu@mit.edu, Krupa Ramasesha, Daniel G. Nocera, and Andrei Tokmakoff ...
10. 98%PHYS 351 - Ultrafast dynamics at the air/water interface investigated with time-resolved electronic sum-frequency generation (TR-ESFG) spectroscopy
PHYS 351 Ultrafast dynamics at the air/water interface investigated with time-resolved electronic sum-frequency generation (TR-ESFG) spectroscopy Kentaro Sekiguchi, ksekiguchi@riken.jp, Shoichi Yamaguchi, shoichi@riken.jp, and Tahei Tahara, tahei@riken.jp. Molecular Spectroscopy Laboratory, RIKEN ...
11. 98%PHYS 111 - Ultrafast X-ray spectroscopy and imaging of chemical and physical processes
PHYS 111 Ultrafast X-ray spectroscopy and imaging of chemical and physical processes Xiaodi Li, Brian Ahr, Christopher M. Laperle, and Christoph Rose-Petruck, Christoph_Rose-Petruck@brown.edu. Department of Chemistry, Brown University, 324 Brook Str, Providence, RI 02912 Ultrafast high-intensity laser ...
12. 98%COLL 330 - Ultrafast dissociation of excitons in quantum dots
COLL 330 Ultrafast dissociation of excitons in quantum dots Abdelaziz Boulesbaa, aboules@emory.edu, Jier Huang, jhuang8@emory.edu, Zhuangqun Huang, and Tianquan Lian, tlian@emory.edu. Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, GA 30322 Multiple exciton generation, by which ...
13. 98%COLL 123 - Ultrafast dynamics of electron transfer and solvation processes at ammonia and water ice/metal interfaces
COLL 123 Ultrafast dynamics of electron transfer and solvation processes at ammonia and water ice/metal interfaces Martin Wolf, wolf@physik.fu-berlin.de, Dept. of Physics, Freie Universitaet Berlin, Arnimallee 14, Berlin, 14195, Germany The ultrafast dynamics of interfacial electron transfer are studied ...
14. 97%PHYS 304 - Ultrafast magnetization dynamics in colloidal magnetic nanocrystals
PHYS 304 Ultrafast magnetization dynamics in colloidal magnetic nanocrystals Chih-Hao Hsia, chhsia@mail.chem.tamu.edu, Tai-Yen Chen, tychen@mail.chem.tamu.edu, and Dong Hee Son, dhson@mail.chem.tamu.edu. Department of Chemistry, Texas A&M University, College Station, TX 77842 Ultrafast magnetization ...
15. 97%PHYS 329 - Applications of ultrafast 2-D infrared spectroscopy to studies of the Fe-hydrogenase enzyme system
PHYS 329 Applications of ultrafast 2-D infrared spectroscopy to studies of the Fe-hydrogenase enzyme system A. Ian Stewart 1, M Towrie 2, Ian P Clark 2, Anthony W. Parker 2, Saad Ibrahim 3, Chris J Pickett 3, and Neil T Hunt, nhunt@phys.strath.ac.uk 1. (1) Department of Physics, University of Strathclyde ...
16. 97%PHYS 303 - Ultrafast dynamics in single-walled carbon nanotubes
PHYS 303 Ultrafast dynamics in single-walled carbon nanotubes David J. Styers-Barnett 1, Brian P. Mehl 1, Brittany C. Westlake, westlake@email.unc.edu 2, and John M. Papanikolas, john_papanikolas@unc.edu 1. (1) Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, (2) Department ...
17. 97%INOR 931 - Ultrafast exciton dynamics in OLED materials
INOR 931 Ultrafast exciton dynamics in OLED materials Pavel Anzenbacher Jr., pavel@bgsu.edu, Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, 141 Overman Hall, Bowling Green, OH 43403 Achieving control over the dynamics of excited states is crucial for ...
18. 96%PHYS 620 - Ultrafast infrared spectroscopy of dilute HOD in aqueous salt solutions
PHYS 620 Ultrafast infrared spectroscopy of dilute HOD in aqueous salt solutions Yu-Shan Lin, lin5@wisc.edu, Department of Chemistry, University of Wisconsin - Madison, 1101 University Ave, Madison, WI 53706-1322 and J. L. Skinner, skinner@bert.chem.wisc.edu, Department of Chemistry, University of ...
19. 96%PHYS 342 - Ultrafast photophysics of conjugated polyelectrolytes
PHYS 342 Ultrafast photophysics of conjugated polyelectrolytes Gustavo M Moriena, gustavom@chem.ufl.edu 1, Sevnur Komurlu, sevnur@ufl.edu 1, Xiaoyong Zhao, xyzhao@chem.ufl.edu 1, Seoung Ho Lee 1, Hui Jiang, huijiang@chem.ufl.edu 1, Kirk S Schanze, kschanze@chem.ufl.edu 2, and Valeria D. Kleiman, kleiman ...
20. 96%PHYS 340 - Ultrafast time-resolved measurements of a novel organic multichromophore TNT sensing material
PHYS 340 Ultrafast time-resolved measurements of a novel organic multichromophore TNT sensing material Aditya Narayanan, adityann@umich.edu, Department of Macromolecular Science and Engineering, University of Michigan, 930 N.University Avenue, #4830, Ann Arbor, MI 48109 and T. Goodson III, tgoodson ...
21. 95%PHYS 341 - Ultrafast magnetization dynamics in cobalt-doped iron oxide nanocrystals: Effect of varying exchange interaction
PHYS 341 Ultrafast magnetization dynamics in cobalt-doped iron oxide nanocrystals: Effect of varying exchange interaction Chih-Hao Hsia, chhsia@mail.chem.tamu.edu, Tai-Yen Chen, tychen@mail.chem.tamu.edu, and Dong Hee Son, dhson@mail.chem.tamu.edu. Department of Chemistry, Texas A&M University ...
22. 95%PHYS 250 - Ultrafast 1- and 2-D infrared studies of complex chemical reactions
PHYS 250 Ultrafast 1- and 2-D infrared studies of complex chemical reactions Charles B. Harris, cbharris@berkeley.edu, Karma R. Sawyer, karma@berkeley.edu, James F. Cahoon, jfcaho@berkeley.edu, and Jacob P. Schlegel. Department of Chemistry, University of California at Berkeley, Berkeley, CA 94720 ...
23. 95%INOR 985 - Ultrafast dynamics in the MLCT excited states of Ru(II) and Os(II) coordination complexes
INOR 985 Ultrafast dynamics in the MLCT excited states of Ru(II) and Os(II) coordination complexes John M. Papanikolas, john_papanikolas@unc.edu, Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599 We have used femtosecond transient absorption spectroscopy to address the fundamental ...
24. 95%PHYS 445 - Ultrafast coherent plasmon dynamics of individual metal nanostructures
PHYS 445 Ultrafast coherent plasmon dynamics of individual metal nanostructures Alexandria Kappus, alex63@u.washington.edu, C. C. Neacsu, neacsu@u.washington.edu, and M. B. Raschke, raschke@chem.washington.edu. Department of Chemistry, University of Washington, 36 Bagley Hall, Seattle, WA 98195 The ...
25. 95%PHYS 681 - Dynamics and control of ultrafast nonadiabatic processes
PHYS 681 Dynamics and control of ultrafast nonadiabatic processes Albert Stolow, Albert.Stolow@nrc.ca, Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada Time-Resolved Coincidence Imaging Spectroscopy makes use of 3D particle ...
26. 95%PHYS 301 - Taking it to the limit: Ultrafast dynamics of heat transport over ultrasmall distances
PHYS 301 Taking it to the limit: Ultrafast dynamics of heat transport over ultrasmall distances Jeffrey A. Carter, jcarter3@uiuc.edu, Zhaohui Wang, and Dana D. Dlott. Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801 We have developed a new method for studying the ...
27. 95%PHYS 345 - Aqueous hydroxide ion transport dynamics probed using ultrafast vibrational echo experiments
PHYS 345 Aqueous hydroxide ion transport dynamics probed using ultrafast vibrational echo experiments Sean T Roberts, seanr@mit.edu, Poul B. Petersen, poul@mit.edu, Krupa Ramasesha, and Andrei Tokmakoff. Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Room 6-030 ...
28. 95%PHYS 112 - Ultrafast X-ray scattering studies of structural dynamics
PHYS 112 Ultrafast X-ray scattering studies of structural dynamics Kelly J. Gaffney, kgaffney@slac.stanford.edu, Stanford Linear Accelerator Center, Stanford University, 2575 Sand Hill Road, Menlo Park, CA 94025 Measuring atomic resolution images of materials with x-ray photons during chemical reactions ...
29. 95%COMP 197 - Temperature dependent structural dynamics of the Villin Headpiece Helical Subdomain: An ultrafast folding protein
COMP 197 Temperature dependent structural dynamics of the Villin Headpiece Helical Subdomain: An ultrafast folding protein Lauren Wickstrom, lwick442@yahoo.com, Stony Brook University, Biochemistry and Structural Biology, Stony Brook, NY 11794, Scott H. Brewer, Chemistry Department, Franklin & ...
30. 94%COLL 333 - Ultrafast electron solvation and transfer dynamics at protic-solvent/TiO2 interfaces
COLL 333 Ultrafast electron solvation and transfer dynamics at protic-solvent/TiO2 interfaces Hrvoje Petek, Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 We study the electron solvation and reverse charge transfer dynamics of partially solvated 搘et?electrons ...

31. 93%PHYS 318 - New insights into electronic structures of semiconductor nanocrystals through single-particle and ultrafast spectroscopies
PHYS 318 New insights into electronic structures of semiconductor nanocrystals through single-particle and ultrafast spectroscopies Victor I. Klimov, Chemistry Division, Los Alamos National Laboratory, MS-J567, Los Alamos, NM 87545 Semiconductor nanocrystals are stable, spectrally tunable chromophores ...
32. 92%PHYS 25 - Nanoparticle induced light-harvesting membrane protein deformation (LH2) revealed by ultrafast spectroscopic study of the excitonic states
PHYS 25 Nanoparticle induced light-harvesting membrane protein deformation (LH2) revealed by ultrafast spectroscopic study of the excitonic states Yu-Xiang Weng, yxweng@aphy.iphy.ac.cn, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Hai Dian Qu Zhong Guan Cun ...
33. 91%PHYS 685 - Multidimensional wave packet dynamics in ultrafast molecular fragmentation
PHYS 685 Multidimensional wave packet dynamics in ultrafast molecular fragmentation Thomas C Weinacht, tweinacht@sunysb.edu and Sarah R Nichols. Department of Physics and Astrononmy, Stony Brook University, Stony Brook, NY 11794-3800 This talk will focus on the interpretation of pump-probe measurements ...
34. 90%PHYS 113 - Probing charge-transfer processes in solution with ultrafast X-ray absorption spectroscopy
PHYS 113 Probing charge-transfer processes in solution with ultrafast X-ray absorption spectroscopy Munira Khalil, mkhalil@chem.washington.edu, Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700 This talk will outline the use of time-resolved x-ray absorption spectroscopy ...
35. 13%PHYS 227 - Two-dimensional electronic spectroscopy of photosynthetic complexes
PHYS 227 Award Address (Ahmed Zewail Award in Ultrafast Science and Technology, sponsored by Ahmed Zewail Endowment Fund established by Newport Corporation). Two-dimensional electronic spectroscopy of photosynthetic complexes Graham R Fleming, GRFleming@lbl.gov 1, Elizabeth Read 2, Tessa Calhoun 2 ...
36. 11%INOR 932 - Structural dynamics of photoactive metal complexes in solar energy conversion
... their structures with atomic resolution and sufficient time resolution is crucial in correlating structures with molecular properties. Combining ultrafast optical and x-ray transient absorption spectroscopy, the structural dynamics of several important metal complexes can be obtained, including their ...
37. 11%PHYS 346 - Local interfacial electronic structure of thin pentacene films on Si(111)
... -0041 Organic photovoltaic (OPV) devices offer a promising route to low-cost solar energy harvesting. These systems have demonstrated heterogeneous ultrafast charge transfer dynamics in part due to complex micro and nanoscale disorder at semiconductor domain interfaces. We have investigated the effects ...
38. 11%COLL 329 - Watching excitations diffuse and charges recombine at interfaces in organic photovoltaic materials
... separation, excitation transport, and charge recombination at the interfaces of polymer blend organic photovoltaic materials are examined using ultrafast visible pump ?infrared probe spectroscopy. Native vibrational modes of both the electron donating polymers and electron accepting fullerenes are ...
39. 11%PHYS 251 - Nonequilibrium dynamics studied with transient Fourier transform 2-D IR spectroscopy
... 48109 The power of two-dimensional infrared (2DIR) spectroscopy to reveal equilibrium vibrational coupling, loss of transition frequency memory and ultrafast chemical exchange has been firmly established in recent years. A long standing challenge of ultrafast spectroscopy is to study chemical reaction ...
40. 11%PHYS 331 - Charge transfer induced proton-coupled electron transfer
... , the biphenyl molecule undergoes an intramolecular transition that transfers charge from the hydroxy end of the molecule to the nitro- end. Ultrafast measurements show direct evidence that relaxation to ground state (i.e. back electron transfer) is coupled to proton transfer from the hydroxyl group ...

41. 11%PHYS 114 - Femtosecond and picosecond X-ray spectroscopy in chemical dynamics research
... will present our recent results on the light induced structural dynamics of molecules in solution using an optical probe/X-ray probe method based on ultrafast X-ray absorption spectroscopy. This approach was applied to photoexcited coordination chemistry compounds next to nascent atomic radicals in ...
42. 10%PHYS 374 - Electron transfer dynamics from organic dyes to semiconductor nanocrystalline films
... organic dyes (xanthene, coumarin, and stylene derivatives) to different semiconductors (TiO 2, SnO 2, In 2O 3, ZnO) were investigated using both ultrafast IR and visible transient absorption spectroscopy. The IR injection dynamics to the different semiconductors were directly correlated with visible ...
43. 10%PHYS 298 - Charge and energy transfer dynamics in nanoscale systems
... of the nanocrystal only. To examine this assumption we have prepared and examined a series of nanocrystalline donor-acceptor systems that undergo ultrafast photo-induced electron transfer. A particular attribute of systems like nanocrystalline quantum dots is that the electronic levels can be modified ...
44. 10%PHYS 686 - Optical control in simple chemical systems
... chemical systems Roseanne J. Sension, rsension@umich.edu, FOCUS Center, University of Michigan, 930 N. University, Ann Arbor, MI 48109 Advances in ultrafast laser technology have led to the development of sophisticated spectroscopic techniques to probe dynamics in complex systems. But chemistry is not ...
45. 10%PHYS 314 - Controlling the ablation of materials with pairs of femtosecond laser pulses
... . Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, IL 60607 We report the synergistic effect of a pair of ultrafast laser pulses on the ablation of materials and on the properties of the resulting plasma. Using Si<111> as an example, we compare the ratio ...
46. 10%INOR 10 - Experimental visualizations by 2-D IR of water associating with peptides and ions
... -Hung Kuo, Dmitriy Y. Vorobyev, Yung-Sam Kim, and Robin M. Hochstrasser. Department of Chemistry, University of Pennsylvania, Philadelphia, PA 10104 Ultrafast two-dimensional infrared spectra (2D IR) expose the structural dynamics of the water solvation of polar bonds of various solutes. The dynamics ...
47. 10%PHYS 328 - Infrared spectroscopy of tritiated water
... , tokmakof@MIT.EDU. Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 Studies of water with ultrafast nonlinear infrared spectroscopy have commonly used isotopically dilute solutions, which provide a local probe of hydrogen bond dynamics. We have ...
48. 10%PHYS 335 - Photoinduced charge separation at CdSe quantum dots and Re-bipyridyl complex interface
... Drive, Atlanta, GA 30322 Photoinduced charge separation between CdSe quantum dots/adsorbed Re(CO)3Cl(dcbpy) complex (ReCOA) was investigated by both ultrafast infrared and visible time resolved spectroscopy. Optical excitation of the CdSe nanoparticle led to absorbance decrease (bleach) of three CO ...
49. 10%PHYS 302 - Watching electrons move in polymer blend photovoltaic materials
... of photoinduced charge separation and the motion of the resulting electrons are examined in an organic photovoltaic material with a combination of ultrafast two-dimensional infrared and visible pump ?infrared probe spectroscopy. The carbonyl stretch of a functionalized fullerene, PCBM, is probed as ...
50. 10%PHYS 467 - Electron transfer at single CdSe/ZnS quantum dot/adsorbate interface
... of quantum dots (QDs) in novel solar cells and because of its ability to generate multiple excitons with one absorbed photon. Ensemble averaged ultrafast spectroscopic studies show that photoinduced interfacial electron transfer (IFET) between CdS or CdSe QDs and Rhodamine B molecules exhibit multi ...


51. 10%PHYS 343 - 1,2,3,4,5-Pentamethyl-cyclopentadiene dynamics probed by photoionization
... , Brown University, 324 Brook St, Providence, RI 02912 1,2,3,4,5-pentamethyl-cyclopentadiene has, upon excitation of the 1B2 state at 4.65 eV, an ultrafast curve crossing dynamics that returns the molecule to the ground state via the 2A1 state. Using time-resolved mass spectrometry and photoelectron ...
52. 10%CHED 396 - Energy transfer in DNA oligomers
... the underlying causes of this photodamage. Our research is centered in studying synthetic DNA oligonucleotides and monomers of DNA bases using ultrafast spectroscopy to gain a greater understanding of energy transfer within the genetic material. It is well known that the absorption of a photon of 266nm ...
53. 10%PHYS 726 - Infrared spectroscopic probes of dynamics in water, salt solutions, reverse micelles, and membrane proteins
... reverse micelles, and membrane proteins James L. Skinner, skinner@chem.wisc.edu, Department of Chemistry, University of Wisconsin, Madison, WI 53706 Ultrafast and frequency-domain infrared spectroscopy can provide an excellent probe of the structure and dynamics of condensed phase systems due to the ...
54. 10%PHYS 22 - 2-D Optical spectroscopy of photosynthetic light harvesting complexes
... E119, Chicago, IL 60637 Two dimensional electronic spectroscopy provides detailed information about electronic structure and electronic dynamics on ultrafast timescales. Probing chromophores embedded within photosynthetic complexes with this technique, we are able to observe the underlying design principles ...
55. 10%PHYS 334 - Optimal control of photoproducts
... pulses perturb a molecule's excited state dynamics modulating the process photochemical outcome. Combined with pulse shaping and optimal control, ultrafast pulses provide a tool to arbitrarily modify molecular behavior. Azobenzene is a photochromic molecule with two possible stable isomers. Upon excitation ...
56. 10%PHYS 727 - New insight into the length and time scales of the hydrogen bond network of liquid H2O
... of the OH stretching vibration are found to be particularly sensitive probes of the fully resonant hydrogen bond network of liquid H 2O. Ultrafast memory loss and energy redistribution are observed in which pure H 2O appears to be an extremely strongly coupled system with no clear separation in relaxation ...
57. 10%PHYS 683 - Optimal control as a molecular learning tool
... in a dendritic novel macromolecule. Manipulation of excited state dynamics has been successfully achieved using phase- and amplitude 杝haped ultrafast laser pulses. Changes on the excited state dynamics will influence the coupling strength between donor and acceptor moieties, inducing a modulation of ...
58. 10%PHYS 527 - Ab initio simulation of the 2-D vibrational spectrum of dimanganese decacarbonyl
... methodology of two-dimensional nuclear magnetic resonance spectroscopy and applies it to vibrational resonances such that 2D IR can be used as an ultrafast probe of molecular dynamics. The goal of this project is to calculate the 2D IR spectrum of dimanganese decacarbonyl from first principles using ...
59. 10%PHYS 78 - Anionic species as electron transfer induced reaction precursors
... -induced intra-cluster electron transfer reveals details of the dynamics associated with free electron-neutral molecule systems. Furthermore, with an ultrafast pump pulse the instant of electron transfer is defined with fs precision. Time resolved probing of the transient anion intermediate affords the ...
60. 10%PHYS 97 - Optically induced dynamic magnetism in superparamagnetic nanocrystals
... the photo excitation, the reduced ionic magnetic moments and the frustration of the magnetic ordering among the magnetic moments resulted in the ultrafast demagnetization. The recovery of the magnetization occurred on two different time scales. The amplitude of the magnetization recovery showed a strong ...
61. 10%PHYS 724 - Reorientational dynamics of water molecules in anionic hydration shells
... from the anion's shell. An analytic extended jump model is designed, which accounts for the simulation results as well as available NMR[5] and ultrafast spectroscopic data[6], and resolves the discrepancy between them. If time permits, we will show how this approach can bring some insight on the structure ...
62. 10%PHYS 54 - Single-exciton optical gain using type-II semiconductor nanocrystals
... recombination. Here, we demonstrate a practical approach for obtaining optical gain in the single-exciton regime, which eliminates the problem of ultrafast Auger decay. Specifically, we develop core/shell hetero-NCs that produce efficient spatial separations between electrons and holes. The resulting ...
63. 10%COLL 78 - Molecules at aqueous interfaces
... using the interface selective methods of second harmonic and sum frequency spectroscopies will be described. Measurements of both equilibrium and ultrafast phenomena will be discussed. The Physical Chemistry of Environmental Interfaces 9:00 AM-1:10 PM, Monday, April 7, 2008 Morial Convention ...
64. 10%PHYS 456 - Artificial molecules
... ' should have an eigenstate spectrum in the vein of molecular orbitals. The eigenstate spectrum of the biexciton has remained elusive due to the ultrafast timescale of relaxation processes in quantum dots which mask observation of the excited states. Here, we show the first, direct observation of excited ...
65. 10%COLL 126 - Visible light photooxidation of Mn complexes covalently attached to TiO2
... of surface complexes leads to interfacial electron transfer in the subpicosecond time scale, as indicated by mixed quantum-classical simulations and ultrafast optical pumpterahertz probe transient measurements. Photoinduced interfacial electron transfer is accompanied by Mn photooxidation, monitored ...
66. 10%PHYS 256 - Atomic solvation dynamics and the breakdown of linear response
... through two well-defined pathways: femtosecond photodetachment of Na ? and photoinduced electron transfer/attachment to Na +. We find that the ultrafast time-resolved solvation of nascent TCPs occurs ~2-3 times more rapidly following attachment than detachment, qualitatively matching results of classical ...
67. 10%COLL 332 - Time-domain ab initio studies of photoinduced electron dynamics at molecule-semiconductor interfaces
... -of-the-art non-adiabatic molecular dynamics techniques and implemented them within time-dependent density functional theory in order to model the ultrafast photoinduced processes in nanoscale materials at the atomistic level, and in real time. The theoretical studies provide an exclusive perspective ...
68. 10%PHYS 170 - Dynamics and spectroscopy of open-shell species in water: The ionization process
... prior to electron ejection. We use broadband transient absorption spectroscopy to monitor the formation of radical and ion species in these ultrafast ionization reactions. The spectroscopy and dynamics of the various open-shell species are complicated by their interaction with the solvent, therefore ...
69. 10%PHYS 232 - Computational spectroscopy of excited-state DNA bases
... allows direct computation of experimental spectroscopic observables. In this contribution, we present simulations of time-resolved photoelectron and ultrafast fluorescence spectra for various DNA bases. The experimental and theoretical spectra are in good agreement and we use this to provide further ...
70. 10%PHYS 210 - Multiple exciton generation in semiconductor quantum dots and applications to third generation solar photon conversion
... prediction has been confirmed by several groups using various spectroscopies over the past few years in several types of QDs. Very efficient and ultrafast multiple exciton generation (MEG) from absorbed single high energy photons has been reported in PbSe, PbS, PbTe, CdSe, InAs and Si QDs. Efficient ...


71. 10%INOR 992 - Interactions of energetically proximate excited-states in platinum(II) charge-transfer complexes
... temperature emission with solvent programmable photoluminescence and transient absorption properties. Steady-state and time-resolved spectroscopy on ultrafast and supra-nanosecond time scales are employed to elucidate the nature of the excited-states exhibited by these complexes. Spectroscopy ...
72. 10%COLL 129 - Electron transfer dynamics at the ZnO (10-10) surface
... an important role in electron transfer across this surface and in electron transport in devices featuring ZnO photoanodes. Additionally, we observe ultrafast sub-20 femtosecond cooling of hot electrons within the ZnO conduction band, suggesting that hot carrier transport may not be feasible in this ...
73. 10%PHYS 612 - Matching-pursuit split-operator Fourier-transform simulations of excited state intramolecular proton transfer in 2-(2-hydroxyphenyl)-benzothiazole
... self-consistent field method. The reported results demonstrate the capabilities of the MP/SOFT method as a valuble computational tool to study ultrafast reaction dynamics in polyatomic systems as well as to validate simulations of complex(nonintegrable) quantum dynamics in multidimensional model systems ...
74. 10%COLL 53 - Photophysics of individual single-walled carbon nanotubes
... -dimensional bound electron杊ole pairs), their robust and unexpectedly unwavering single molecule fluorescence, and their excited state dynamics on ultrafast time scales, including the quantized annihilation of electron杊ole pairs. Interfacial Electron Transfer and Solar Energy Conversion: From ...
75. 8%PHYS 317 - Toward coherent control in the nanoscale
... tools borrowed from coherent control of molecular dynamics with two goals in mind. One is to introduce new function into nanoplasmonics, including ultrafast elements and broken symmetry elements. The second is to develop coherent nanoscale sources and apply them to coherent control of both molecular ...
===================

1. 100%PHYS 132 - Semiconductor quantum dot sensitized multiphoton polymerization
PHYS 132 Semiconductor quantum dot sensitized multiphoton polymerization Nicholas C. Strandwitz, nstrand@engineering.ucsb.edu 1, Anzar Khan 2, Shannon W. Boettcher, sboettcher@chem.ucsb.edu 3, Alexander Mikhailovsky 3, Craig J. Hawker, hawker@mrl.ucsb.edu 2, Thuc-Quyen Nguyen, quyen@chem.ucsb.edu 3 ...
2. 98%PRES 57 - Microreplication and design of biological architectures using mask-directed multiphoton lithography
PRES 57 Microreplication and design of biological architectures using mask-directed multiphoton lithography Jason B. Shear, jshear@biosci.utexas.edu, Department of Chemistry and Biochemistry, University of Texas, 1 University Station A5300, Austin, TX 78712 The study of model cellular systems has benefited ...
3. 11%PHYS 569 - Unimolecular dissociation dynamics of the methylsulfonyl radical using velocity map imaging
... of methylsulfonyl chloride. The spin-orbit state selected Cl(2P 3/2) and Cl(2P 1/2) atomic fragments are detected via [2+1] resonance enhanced multi-photon ionization (REMPI) at 235 nm. Using energy conservation, the total recoil translational energy distribution allows us to determine the internal ...
4. 10%PMSE 405 - 3-D Patterning of polymeric hydrogels for cell guidance
... and trophism, such as nerve growth factor, NGF. The hydrogels have been modified with defined spatial resolution taking advantage of advanced multiphoton laser processing, resulting in patterned volumes of cell adhesion separated by volumes of non-adhesion in agarose and growth factor concentration ...
5. 8%BIOL 117 - Supramolecular 2,3-dihydro-1H-benzo[D]imidazole and zinc(II)-complexes as agents in photodynamic therapy
... techniques are being used in this study to elucidate the electronic and steric factors influencing the DNA binding and the reactivity upon multiphoton excitation at 800nm. Poster Session 5:00 PM-7:00 PM, Tuesday, April 8, 2008 Morial Convention Center -- Hall A, Poster Division of Biological ...




1. Femtosecond dynamic-absorption studies of intermolecular vibrational coherence in bacteriochlorophyll and Zn杙orphyrin charge-transfer dynamics
PHYS 23
Warren F. Beck, beck@chemistry.msu.edu, Kevin L. Dillman, Sanela Lampa-Pastirk, and Katherine R. Shelly. Department of Chemistry, Michigan State University, 3 Chemistry Building, East Lansing, MI 48824
In order to determine the structural nature of the mode-specific reorganization energy that nearly exactly balances the driving forces for primary and secondary electron-transfer reactions in the purple-bacterial reaction center, we have examined the low-frequency vibrational coherence arising from hindered translational and librational intermolecular interactions in bacteriochlorophyll and Zn(II)-porphyrin systems. The mean frequency of the intermolecular modes is consistent with a van der Waals potential that contains large terms from the London dispersion and dipole杁ipole interactions; ion杁ipole and ion杋nduced-dipole interactions make dominant contributions in charge-transfer products. We will discuss new results from the bacteriochlorophyll proteins B777 and B820 that show that ordered intermolecular interactions with first-shell interactions with groups in the surrounding protein medium and adjacent BChl macrocycles exhibit resonance Raman activities that are many times larger than those from the skeletal modes of the macrocycles themselves. We will also discuss new results from studies of Zn(II) meso-tetrakis(N-methylpyridyl)porphyrin in polar solutions, where excited-state intramolecular charge-transfer turns on the ion杁ipole and ion杋nduced-dipole interactions and produces a large change in the intermolecular mode frequency.


Optical Probes of Dynamics in Complex Environments
8:00 AM-12:00 PM, Sunday, April 6, 2008 Morial Convention Center -- Rm. 344, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008


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2. Pump-DFWM-spectroscopy on ?-carotene with shaped femtosecond pulses
PHYS 687
Jurgen Hauer, Tiago Buckup, and Marcus Motzkus, motzkus@staff.uni-marburg.de. Fachbereich Chemie, Philipps-Universitat Marburg, Hans-Meerwein-Strasse, 35037 Marburg, Germany
Coherent control aims at influencing photochemical reaction pathways by modulating the excitation pulse. We present a set of open loop control experiments in which the behaviour on both the electronic ground and excited state are manipulated. The differences between the ground,- and excited state scenarios are discussed by the means of specific control parameters. The molecule under investigation is all-trans-?-carotene, an important biomolecule.

Within the possible control objectives, coherently excited molecular oscillations represent a promising subset. Due to their harmonic behaviour in time, an intuitive control mechanism can be proposed: if an equally spaced sequence of pulses excites a molecular vibration with a period Tvib, the excitation can be mode selective if the subpulse spacing b is equal to Tvib. The feasibility of this control scheme is tested on ground,- and excited state transients by degenerate four wave mixing (DFWM) and Pump朌FWM respectively.

It is found that the ground state vibrations can be controlled and under resonant excitation conditions even enhanced by the application of appropriately spaced multipulses. Coherent control of excited state behaviour is achieved by phase modulating the pump pulse, whereas the DFWM杝equence serves as a heterodyne detection method. On the excited state however it is not the subpulse spacing b but the relative phase c between them that proves to be the most effective control parameter for manipulating the population dynamics.



Optical Probes of Dynamics in Complex Environments
8:00 AM-12:00 PM, Thursday, April 10, 2008 Morial Convention Center -- Rm. 344, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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3. Femtosecond and picosecond X-ray spectroscopy in chemical dynamics research
PHYS 114
Christian Bressler, christian.bressler@epfl.ch, Laboratoire de Spectroscopie Ultrarapide, Ecole Polytechnique Federale de Lausanne, ISIC-BSP, CH-1015 Lausanne, Switzerland
We will present our recent results on the light induced structural dynamics of molecules in solution using an optical probe/X-ray probe method based on ultrafast X-ray absorption spectroscopy. This approach was applied to photoexcited coordination chemistry compounds next to nascent atomic radicals in aqueous solutions. Structural changes were monitored for key processes, including charge transfer and spin crossover processes. In a recent development, femtosecond hard X-ray pulses have been extracted from the SLS synchrotron. We will present our femtosecond results on photoexcited Fe(II) based spin crossover complexes, where we follow, by ultrafast XANES, the evolution of the system from the initially excited singlet state to the lowest excited quintet state, within 1 ps. An outlook to new sources of pulsed hard x-radiation, e.g., XFELs, will be given.


Optical Probes of Dynamics in Complex Environments
8:00 AM-12:00 PM, Monday, April 7, 2008 Morial Convention Center -- Rm. 344, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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4. Controlling the ablation of materials with pairs of femtosecond laser pulses
PHYS 314
Robert J Gordon, rjgordon@uic.edu, Yongtao Cheng, Zhan Hu, Yaoming Liu, Ting Lu, Sima Singha, and Tana E. Witt. Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor Street, Chicago, IL 60607
We report the synergistic effect of a pair of ultrafast laser pulses on the ablation of materials and on the properties of the resulting plasma. Using Si<111> as an example, we compare the ratio of the fluorescence from discrete transitions of neutral and ionized Si produced by a pair of pulses to that produced by a single pulse of the same total energy. We find that the fluorescence enhancement ratio increases with the delay between the pulses and decreases with the total pulse energy. We explain these results by a mechanism in which the first pulse melts the surface to produce a nanoscale liquid film, and the second pulse is absorbed more strongly by the molten phase. This mechanism is supported by reflectivity and AFM measurements. Similar behavior is observed for Cu, whereas qualitatively different trends are observed for a variety of dielectrics. We further observe for Si that the fluorescence is strongly polarized. The polarization increases with delay and pulse energy and decreases with wavelength for discrete as well as continuum emission. Under appropriate conditions, greater than 90% polarization was observed, suggesting strong anisotropy of the plasma.


Spectroscopy, Chemistry, and Imaging through Nanophotonics
1:20 PM-5:20 PM, Wednesday, April 9, 2008 Morial Convention Center -- Rm. 340/341, Oral

Division of Physical Chemistry

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5. Photoinduced and dark bimolecular reactions in aqueous solutions of ruthenium (II)-tris-(2,2'-bipyridine) upon high intensity femtosecond laser excitation
INOR 934
Alexander N. Tarnovsky, atarnov@bgsu.edu, Department of Chemistry & Center for Photochemical Sciences, Bowling Green State University, Bowling Green, OH 43403
The structures of reaction intermediates can be obtained using a novel laser pump/x-ray absorption probe technique (tr-XAS), in which high spatial resolution of x-ray probe radiation is combined with high temporal resolution of femtosecond laser photoexcitation. For reconstruction of the local structures from tr-XAS, the knowledge of product yields under high intensity photoexcitation conditions is required. Considerable efforts have been made to describe the photophysics and photochemistry of [RuII(bpy)3]2+ complex, which is a model system for metal-to-ligand charge transfer reaction as well a prototype of d6 polypyridine complexes of second-row transition metals. Recent tr-XAS experiments on aqueous [RuII(bpy)3]2+ with 50-ps time resolution have provided structural information on the complex in the 3MLCT triplet excited state. Very few studies of this complex, however, dealt with issues of high excitation intensities and large solute concetrations. Here, we discuss a femtosecond pump-probe investigation of the photochemistry of [RuII(bpy)3]2+ (癠20 mM) in aqueous solutions initiated by excitation with 400 nm, ~130 fs laser pulses of high power density (up to 2 TW cm-2). Transient absorption difference spectra in the 345?C660 nm range measured with delay times of up to 1 ns at various energy fluence enable observation of the following photoproducts: the complex in the 3MLCT triplet excited state, the reduced form [RuII(bpy)3]+, the oxidized form [RuIII(bpy)3]3+, and the hydrated electron eaq. The product formations mechanisms are discussed.


Spectroscopy of Inorganic Systems
2:00 PM-5:25 PM, Wednesday, April 9, 2008 Morial Convention Center -- Rm. 219, Oral

Division of Inorganic Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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6. Ultrafast dynamics in single-walled carbon nanotubes
PHYS 303
David J. Styers-Barnett1, Brian P. Mehl1, Brittany C. Westlake, westlake@email.unc.edu2, and John M. Papanikolas, john_papanikolas@unc.edu1. (1) Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, (2) Department of Chemistry, University of North Carolina at Chapel Hill, Caudill and Kenan Laboratories, Chapel Hill, NC 27599-3290
We have used femtosecond transient absorption spectroscopy to examine the excited state dynamics of single-walled carbon nanotube (SWNT) bundles embedded in polymer matrices. The SWNTs are excited by a femtosecond pump pulse and probed using a white-light continuum. We observe a structured transient absorption spectrum consisting of a series of narrow induced transmission (IT) and induced absorption (IA) bands, which appear on a time scale shorter than our instrument response (200 fs) and persist for up to 100 ps. Analysis of the transient absorption spectra suggests that the narrow features are the result of a nonlinear optical response in the SWNTs. The induced absorption bands are attributed to biexciton formation in which a second electron-hole pair is formed in close proximity to already existing exciton, producing a four-particle excitation. Transient absorption spectra obtained at a series of pump-probe delay times reflect the exciton dynamics following excitation.


Optical Probes of Dynamics in Complex Environments
1:20 PM-5:20 PM, Wednesday, April 9, 2008 Morial Convention Center -- Rm. 344, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

-----------------------------------------

7. Ultrafast magnetization dynamics in cobalt-doped iron oxide nanocrystals: Effect of varying exchange interaction
PHYS 341
Chih-Hao Hsia, chhsia@mail.chem.tamu.edu, Tai-Yen Chen, tychen@mail.chem.tamu.edu, and Dong Hee Son, dhson@mail.chem.tamu.edu. Department of Chemistry, Texas A&M University, College Station, TX 77842
The dynamics of photo-induced magnetization in chemically synthesized Co-doped iron oxide nanocrystals were investigated by femtosecond Faraday rotation measurements. Through the controlled doping of Co, nanocrystal samples of varying Co content were prepared ranging from Fe3O4 to CoFe2O4. The effect of Co doping, which influences the exchange interaction between the ionic magnetic moments, on the dynamics of the demagnetization and its recovery were investigated. The time scale and the amplitude of the changes in magnetization following the spin flip excitation were dependent on Co content. The amplitude of the time-dependent differential magnetization was correlated with the spin coherence length, which increases with the strength of the exchange interaction.


PHYS Poster Session - Optical Probes of Dynamics in Complex Environments
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Sci-Mix

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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8. Charge transfer induced proton-coupled electron transfer
PHYS 331
Jared J. Paul, jpaul@unc.edu, Brittany C. Westlake, westlake@email.unc.edu, M. Kyle Brennaman, kyleb@email.unc.edu, John M. Papanikolas, john_papanikolas@unc.edu, and Thomas J. Meyer, tjmeyer@email.unc.edu. Department of Chemistry, University of North Carolina at Chapel Hill, Caudill and Kenan Laboratories, Chapel Hill, NC 27599-3290
The relaxation dynamics of a photoexcited hydrogen bound 4-hydroxy-4'-nitrobiphenyl and t-butylamine association complex have been followed using both femtosecond and nanosecond transient absorption spectroscopy. Upon photoexcitation, the biphenyl molecule undergoes an intramolecular transition that transfers charge from the hydroxy end of the molecule to the nitro- end. Ultrafast measurements show direct evidence that relaxation to ground state (i.e. back electron transfer) is coupled to proton transfer from the hydroxyl group to the base. Partitioning to a second path involving dissociation of the hydrogen-bonded complex to give a deprotonated form is shown through nanosecond transient absorption spectroscopy.


PHYS Poster Session - Optical Probes of Dynamics in Complex Environments
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Sci-Mix

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

--------------------------------------------


9. Ultrafast coherent plasmon dynamics of individual metal nanostructures
PHYS 445
Alexandria Kappus, alex63@u.washington.edu, C. C. Neacsu, neacsu@u.washington.edu, and M. B. Raschke, raschke@chem.washington.edu. Department of Chemistry, University of Washington, 36 Bagley Hall, Seattle, WA 98195
The coherent electron dynamics in metal nanostructures, with a temporal response as short as just several femtoseconds, controls local field enhancement as well as excitation and quenching of coupled molecular excitations. To avoid the heterogeneous broadening of ensemble measurements it is desirable to perform corresponding studies on the single particle level. Here, we demonstrate the resonant and off-resonant coherent dynamics of the plasmon response of individual, clean and adsorbate covered gold nanotips. We use second-harmonic interferometric autocorrelation with sub-10 fs excitation. The femtosecond temporal response of the plasmon polariton is found to be sensitive with respect to the structural parameters of the tips in terms of apex radius and cone angle and can be described by quasi-static model calculations.


PHYS Poster Session - Nanostructured Materials and Nanophotonics
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Sci-Mix

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

---------------------------------------------

10. Photopolymerization of conductive metal nanoparticles
PHYS 506
Xichen Cai, xichenc@bgsu.edu, Kelechi C Anyaogu, akelech@bgnet.bgsu.edu, and Douglas C. Neckers, neckers@photo.bgsu.edu. Center for Photochemical Sciences, Bowling Green State University, 132 Overman Hall, Bowling Green, OH 43403
Polymeric conductive nanomaterials are expected to have various applications as chemical or biosensors, in transistors and switches, as photovoltaic cells, electrochromic devices, and optically conducting materials. However, the synthesis of conductive nanomaterials in a desired two- or three-dimensional structure remains a challenge. In general, chemical and electrochemical polymerization are common methods to produce conducting polymers in which nanoparticles (NPs) are embedded. We report herein the photopolymerization of 5-mercapto-2,2'-bithiophene (BTSH) functionalized metal (Au, Ag, and Cu) NPs. The three-dimensional structure of aggregated NPs was identified using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Electron transfer from ligand to metal was confirmed by femtosecond transient absorption measurements. Ligand radical cation coupling caused the linking of the metal nanoparticles. Photopolymerization of BTSH functionalized metal NPs provides a useful method for making two- or three-dimensional designs of conductive polymeric nanomaterials.


PHYS Poster Session - Nanostructured Materials and Nanophotonics
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Sci-Mix

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

----------------------------------------------

11. Ultrafast dynamics at the air/water interface investigated with time-resolved electronic sum-frequency generation (TR-ESFG) spectroscopy
PHYS 351
Kentaro Sekiguchi, ksekiguchi@riken.jp, Shoichi Yamaguchi, shoichi@riken.jp, and Tahei Tahara, tahei@riken.jp. Molecular Spectroscopy Laboratory, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama, Japan
We developed a new surface-selective time-resolved nonlinear spectroscopy, femtosecond time-resolved electronic sum-frequency generation (TR-ESFG) spectroscopy, to investigate ultrafast dynamics at liquid interfaces. Its advantage over conventional time-resolved second harmonic generation spectroscopy is that it provides spectral information, which is realized by the multiplex detection of the sum frequency signal using a broadband white light continuum and a multichannel detector. With this new method, we examined the photo-induced dynamics of a surface active dye (rhodamine 800) at the air/water interface and successfully observed transient electronic spectra of interfacial molecules for the first time. We found that the relaxation dynamics exhibited three time constants of 0.32 ps, 6.4 ps, and 0.85 ns, and the 6.4-ps component corresponds to an interface-specific deactivation process. With the TR-ESFG spectroscopy, we can now investigate dynamics at liquid interface as thoroughly as we do for the dynamics in bulk solutions with the conventional femtosecond time-resolved absorption spectroscopy.


PHYS Poster Session - Optical Probes of Dynamics in Complex Environments
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

----------------------------------------------

12. Ultrafast dynamics in the MLCT excited states of Ru(II) and Os(II) coordination complexes
INOR 985
John M. Papanikolas, john_papanikolas@unc.edu, Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599
We have used femtosecond transient absorption spectroscopy to address the fundamental photophysics of metal-to-ligand charge-transfer (MLCT) excited states in both symmetric and asymmetric (i.e. mixed-ligand) complexes. We have examined the flow of energy between a chromophore and ligand bound energy acceptor, from one ligand to another (i.e. ILET), and between two fragments on the same ligand. Our experiments have touched on vibrational cooling, intersystem crossing, and excited state solvation. They have led to a detailed picture of the excited state potentials in polar solvents, provided insight into the nature of the excited state wavefunctions, and the partitioning of excess optical excitation energy between molecular vibrations (inner sphere) and solvent interactions (outer sphere).


Spectroscopy of Inorganic Systems
9:00 AM-1:20 PM, Thursday, April 10, 2008 Morial Convention Center -- Rm. R03, Oral

Division of Inorganic Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

-----------------------------------------------

13. Advances in structural analyses of complex molecules
INOR 35
Keith O. Hodgson, Department of Chemistry and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, CA 94309
Structural characterization has played a seminal role in our understanding of the function and reactivity of metal ion sites in many bioinorganic systems. Crystallography and x-ray absorptionspectroscopy have contributed greatly in this regard, especially to understanding of complex multicomponent enzyme systems like nitrogenase. Several examples will be used to illustrate the current "state of the art". The field is poised for major new developments in x-ray studies with the coming of the world's first x- ray free electron laser sources like the LCLS at Stanford in the next few years. Such x-ray beams will have much higher peak brightness (more than 10**10 and shorter pulses(femtosecond rather than picosecond regime) than currently available. Examples will be used to illustrate the potential of this new class of sources for study of structural dynamics on the femtosecond time scale.


Celebrating Bioinorganic, Supramolecular, Lanthanide and Actinide Chemistry with Ken Raymond
8:30 AM-1:15 PM, Sunday, April 6, 2008 Morial Convention Center -- Rm. 218, Oral

Division of Inorganic Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

--------------------------------------------------

14. First-principles approach to the anharmonic vibrational properties of biomolecules
PHYS 166
Jianping Wang, jwang@iccas.ac.cn, Kaicong Cai, Xiaoyan Ma, and Guixiu Wang. Molecuar Dynamics Laboratory, Institute of Chemistry, Chinese Academy of Sciences, No. 2 1st North St. Zhongguancun, Haidian District, Beijing, 100080, China
Femtosecond two-dimensional infrared (2D IR) spectroscopy can be used to monitor structures and dynamics of molecules in condensed phases by mapping out time-dependent vibrational couplings. The framework of a 2D IR spectrum is anharmonic vibrational motions. Very recently we have shown that all the diagonal and mixed-mode anharmonicities of the 3N-6 modes of a molecular system can be obtained by first-principles computations and based on which all-mode 1D and 2D IR spectra can be simulated. In this work, we further examine the anharmonic vibrational parameters of biomolecules, including peptides, nucleic acids, lipids, as well as sugars, using the first-principles approach. A polarizable continuum model is used to provide implicit solvent environment for the biomolecules. The characteristics of the structure-dependent anharmonic parameters are discussed.


Optical Probes of Dynamics in Complex Environments
1:20 PM-5:20 PM, Monday, April 7, 2008 Morial Convention Center -- Rm. 344, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

---------------------------------------------------

15. Elucidation of mechanism following adaptive control of complex molecules in solution
PHYS 682
Niels H. Damrauer, niels.damrauer@colorado.edu, Matthew A. Montgomery, matthew.montgomery@colorado.edu, and Erik M. Grumstrup. Department of Chemistry and Biochemistry, University of Colorado at Boulder, Campus Box 215, Boulder, CO 80309
The significance of adaptive femtosecond pulse shaping stems from the use of iterative learning which allows for the control and study of electronically, structurally, and reactively complex systems. This presents a remarkable opportunity for chemists to ask what can be done and learned if light were a controllable reagent. Significant progress has been made but the field's development into a viable interrogative tool requires the new methods to extract mechanistic information about control following unbiased many parameter adaptive searches. Recent efforts in our laboratory have involved adaptive control of photoinduced electron transfer phenomena in transition metal coordination complexes in solution. This talk will discuss progress uncovering control surfaces from statistical analyses of adaptive control results. Such surfaces underscore the molecular system's response to the laser field and can be used to test mechanistic hypotheses.


Optical Probes of Dynamics in Complex Environments
8:00 AM-12:00 PM, Thursday, April 10, 2008 Morial Convention Center -- Rm. 344, Oral

Division of Physical Chemistry

----------------------------------------------------

16. Probing quasiparticle and electron correlations by coherent 2-D spectroscopy
PHYS 164
Shaul Mukamel, smukamel@uci.edu, Darius Abramavicius, Lijun Yang, Zhenyu Li, and Rafal Oszwaldowski. Department of Chemistry, University of California, Irvine, 1102 Natural Sciences II, Irvine, CA 92697-2025
Sequences of femtosecond optical pulses are designed to generate signals that are induced by correlations among elementary excitations. Applications to Frenkel excitons in photosynthetic complexes, Wannier excitons in semiconductor quantum dots and wells, and electrons in molecules will be presented. Specific phase-matching directions can target the correlated dynamics of double excitations. Cross peaks in 2D correlation plots are interpreted in terms of quasiparticle scattering. They reveal the double-exciton wavefunction, projected into products of single-excitons. Uncorrelated double-exciton states do not show up in the spectra due to quantum interference among pathways. The proposed techniques amplify cooperative dynamical features and reveal information on the robustness of quantum states to fluctuating environments.


Optical Probes of Dynamics in Complex Environments
1:20 PM-5:20 PM, Monday, April 7, 2008 Morial Convention Center -- Rm. 344, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

----------------------------------------------------

17. Optimal control of photoproducts
PHYS 334
Daniel G. Kuroda, dkuroda@chem.ufl.edu, Department of Chemistry, University of Florida, PO Box 117200, Gainesville, FL 32603 and Valeria D. Kleiman, kleiman@chem.ufl.edu, Department of Chemistry, Center for Chemical Physics, University of Florida, PO BOX 117200, Gainesville, FL 32611-7200.
We investigate the coherent control of azobenzene's excited state population dynamics by adaptive pulse shaping.

Femtosecond excitation pulses perturb a molecule's excited state dynamics modulating the process photochemical outcome. Combined with pulse shaping and optimal control, ultrafast pulses provide a tool to arbitrarily modify molecular behavior. Azobenzene is a photochromic molecule with two possible stable isomers. Upon excitation, the molecule evolves in the excited surface in a picosencond time scale. Multiple pathways can lead azobenzene back to the ground state. While one pathway produces isomerization, the other one relaxes the system to its initial isomeric form.

The effect excitation pulse modulation has on the deactivation pathways can be followed by measuring ground state bleach. Any changes observed in the population recovery indicate control over the system dynamics. By varying the phase modulation of the excitation pulse we investigate the excited state dynamics and its role in the isomerization process.



PHYS Poster Session - Optical Probes of Dynamics in Complex Environments
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

------------------------------------------------------

18. Ultrafast dynamics of electron transfer and solvation processes at ammonia and water ice/metal interfaces
COLL 123
Martin Wolf, wolf@physik.fu-berlin.de, Dept. of Physics, Freie Universitaet Berlin, Arnimallee 14, Berlin, 14195, Germany
The ultrafast dynamics of interfacial electron transfer are studied for ultrathin ice and ammonia layers adsorbed on Cu(111) and Ru(001) surfaces using femtosecond time- and angle resolved two-photon-photoemission (2PPE) spectroscopy. In this process, photo-injection of electrons from the metal into the conduction band is followed by ultrafast localization and solvation of the excess electron. The subsequent energetic stabilization of these solvated electrons due to nuclear rearrangements of the polar molecular environment is accompanied by an increasing degree of localization. The solvation dynamics is found to strongly depend on the adlayer structure, which can be controlled by the growth conditions and the choice of different substrates as a template. In this talk I will compare the solvation dynamics in several types of ammonia and water adlayers and discuss, in particular, the influence of adsorbate structure, the question of bulk versus surface solvation as well as the role of thermally assisted tunnelling on the electron transfer.


Interfacial Electron Transfer and Solar Energy Conversion: From Molecules to Nanomaterials
2:00 PM-6:00 PM, Monday, April 7, 2008 Morial Convention Center -- Rm. 226, Oral

Division of Colloid & Surface Chemistry

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19. Ultrafast 1- and 2-D infrared studies of complex chemical reactions
PHYS 250
Charles B. Harris, cbharris@berkeley.edu, Karma R. Sawyer, karma@berkeley.edu, James F. Cahoon, jfcaho@berkeley.edu, and Jacob P. Schlegel. Department of Chemistry, University of California at Berkeley, Berkeley, CA 94720
Femtosecond infrared spectroscopy is a valuable experimental tool for investigating the details of complex chemical reactions in ambient solution. UV-pump, IR-probe spectroscopy is first used to elucidate the sequential steps in complex chemical reactions. Transient two-dimensional infrared spectroscopy is then applied to reveal more detailed information about the reactions including the transformation of vibrations from reactants through intermediates to products, molecular anharmonicities and the structure of short-lived transients. The applications of both techniques to the elucidation of complex reaction mechanisms in prototypical organometallic reactions and some important homogeneous catalysis reactions will be discussed.


Optical Probes of Dynamics in Complex Environments
8:00 AM-12:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Rm. 344, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

-------------------------------------------------------

20. Watching the protein mambo: Spectroscopic probes of enzyme dynamics
PHYS 204
Christopher M. Cheatum, christopher-cheatum@uiowa.edu, Jigar N. Bandaria, jigar-bandaria@uiowa.edu, Sarah E. Hill, sarah-hill@uiowa.edu, Samrat Dutta, samrat-dutta@uiowa.edu, and Amnon Kohen. Department of Chemistry, University of Iowa, Iowa City, IA 52242
The structural dynamics of enzymes at the femtosecond to picosecond time scale have been invoked to explain the results of temperature-dependent kinetic-isotope-effect measurements for a number of enzymatic reactions. We report studies of enzyme-ligand interaction dynamics at this time scale. To identify the residues that control the dynamics, we have probed the fluctuations of isozymes and mutants of human carbonic anhydrase. We have also studied enzyme dynamics in a transition-state-analog complex for the enzyme formate dehydrogenase. Our results support a potential role for fast dynamics near the transition state and reveal differences in the nature of enzyme-ligand interaction dynamics in the ground state and in vicinity of the transition state of a reaction.


Optical Probes of Dynamics in Complex Environments
8:00 AM-12:00 PM, Tuesday, April 8, 2008 Morial Convention Center -- Rm. 344, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

--------------------------------------------------------

21. Nanoparticle induced light-harvesting membrane protein deformation (LH2) revealed by ultrafast spectroscopic study of the excitonic states
PHYS 25
Yu-Xiang Weng, yxweng@aphy.iphy.ac.cn, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Hai Dian Qu Zhong Guan Cun Nan San Jie 8 Hao, Beijing, 100080, China
We used femto-second time resolved transient absorbance difference spectroscopy to investigate the membrane protein of a light-harvesting antenna complex (LH2) from photosynthetic bacteria Rb. sphaeroides 2.4.1, which consists of two concentric polypeptide cylinders and ringlike pigment aggregate (B850). The deformation of the protein was induced by self-assembly of LH2 onto nanoparticles of different size. The results show that when size of the nanoparticle approaches the diameter of either the inner or the outer polypeptide cylinder, it would induce a largest protein deformation, giving rise to a shorter excited-state life time of B850. This provides a quantitative example of size-matching interaction between the protein and the nanopartilces.


Optical Probes of Dynamics in Complex Environments
8:00 AM-12:00 PM, Sunday, April 6, 2008 Morial Convention Center -- Rm. 344, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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22. Long-range proton transfer in aqueous acid-base reactions
PHYS 723
Bradley J. Siwick, bradley.siwick@mcgill.ca1, Jocelyn Cox2, and Huib J. Bakker, bakker@amolf.nl2. (1) Departments of Chemistry and Physics, McGill University, 801 Sherbrooke St. West, Montreal, QC H3A 2K6, Canada, (2) FOM - AMOLF, Kruislaan 407, 1098 SJ Amsterdam, Netherlands
We have investigated the mechanism of proton transfer (PT) between the photo-acid 8-hydroxy-1,3,6-pyrenetrisulfonic acid (HPTS) and acetate in aqueous solution by probing the vibrational resonances of HPTS, acetate and the hydrated proton with femtosecond mid-infrared laser pulses. We find that PT in this model system takes place in a distribution of hydrogen-bound reaction complexes that differ in the number of water molecules separating the acid and the base. The number of intervening water molecules ranges from 0 to 5, which together with a strongly distance-dependent PT rate explains the observed highly non-exponential reaction kinetics. The kinetic isotope effect for the reaction is determined to be 1.5, indicating that tunneling does not play a significant role in the transfer of the proton. Rather, the transfer mechanism is best described in terms of the adiabatic proton transfer picture as it has been formulated by J. T. Hynes and coworkers, where solvent fluctuations play an essential role in forming the correct hydrogen-bond configuration and solvent polarization to facilitate PT.


Optical Probes of Dynamics in Complex Environments
1:20 PM-5:00 PM, Thursday, April 10, 2008 Morial Convention Center -- Rm. 344, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

------------------------------------------------------

23. Taking it to the limit: Ultrafast dynamics of heat transport over ultrasmall distances
PHYS 301
Jeffrey A. Carter, jcarter3@uiuc.edu, Zhaohui Wang, and Dana D. Dlott. Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801
We have developed a new method for studying the propagation of energy into and through molecules using an ultrafast heat bath.1 The heat bath, a gold substrate, is flash-heated up to 1000 K in approximately 1 ps with a femtosecond laser pulse. A self-assembled monolayer, attached to the heat bath at one end by a Au-S bond, heats as thermal energy surges into the molecules. The resulting dynamics are monitored with picosecond resolution using vibrational sum-frequency generation (SFG) spectroscopy. Due to the coherent nature of the SFG response, the presence of thermal disorder with the monolayer can be observed.

This material is based upon work supported by the National Science Foundation under award DMR 0504038 and the Air Force Office of Scientific Research under award FA9550-06-1-0235.

1. Z. Wang, et al. Science. 317. 787 (2007)



Optical Probes of Dynamics in Complex Environments
1:20 PM-5:20 PM, Wednesday, April 9, 2008 Morial Convention Center -- Rm. 344, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

--------------------------------------------------------

24. Ultrafast infrared spectroscopy of dilute HOD in aqueous salt solutions
PHYS 620
Yu-Shan Lin, lin5@wisc.edu, Department of Chemistry, University of Wisconsin - Madison, 1101 University Ave, Madison, WI 53706-1322 and J. L. Skinner, skinner@bert.chem.wisc.edu, Department of Chemistry, University of Wisconsin, Madison, WI 53706.
Water structure and dynamics in the solvation shells of solutes play an important role in aqueous chemistry. The direct measurement of the dynamics of water molecules in the first solvation shells of Cl-, Br- and I- has been achieved recently by femtosecond midinfrared nonlinear spectroscopy. The previous approach of the electronic structure/molecular dynamics (ES/MD) method for calculating ultrafast vibrational spectroscopy observables is extended to treat multi-species systems. Using this extended ES/MD method, we examined the infrared lineshapes and frequency time-correlation functions for dilute HOD in aqueous salt solutions. The effects of the nature of ions and the salt concentration on the hydrogen bond dynamics are studied and the calculated spectroscopic observables are compared with the experimental results.


PHYS Poster Session - Computational Spectroscopy and Reaction Dynamics
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

-------------------------------------------------

25. Simulations of coherent exciton dynamics in multidimensional spectroscopy
PHYS 183
Darius Abramavicius, dariusa@uci.edu1, Dmitri Voronine, voronine@uci.edu1, and Shaul Mukamel, smukamel@uci.edu2. (1) Department of Chemistry, University of California, Irvine, 1102 Natural Sciences II`, Irvine, CA 92697-2025, (2) Department of Chemistry, University of California Irvine, 1102 Natural Sciences II, Rowland Hall 434, Irvine, CA 92697-2025
A computational algorithm based on the nonlinear exciton equations is presented for simulating and interpreting the response of chromophore aggregates to sequences of femtosecond laser pulses. Applications are made to the Fenna-Matthews-Olson (FMO) light harvesting complex. Some fundamental symmetries of multidimensional optical signals are used to design techniques that can selectively resolve coherent quantum dynamics and incoherent energy dissipation. Simulations show damped oscillations of cross peaks corresponding to evolution of coherences, without interference from incoherent population relaxation. Energy transfer pathways are seen through the redistribution of crosspeak amplitudes. Resolution is enhanced by employing specific pulse polarization configurations to generate chirality杋nduced signals.


Computational Spectroscopy
8:00 AM-12:00 PM, Tuesday, April 8, 2008 Morial Convention Center -- Rm. 342, Oral

Division of Physical Chemistry


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26. Resolving the excited and ground state reaction coordinates in the green fluorescence protein and mutants with dispersed pump-dump probe spectroscopy
PHYS 24
Delmar S. Larsen, dlarsen@ucdavis.edu1, Jie Pan, jiepan@ucdavis.edu1, Mikas Vengris, Mikas.Vengris@ff.vu.lt2, Deborah Stoner-Ma, dstonerma@hotmail.com3, and Peter J. Tonge, peter.tonge@sunysb.edu4. (1) Department of Chemistry, University of California, Davis, One Shields Ave, Davis, CA 95616, (2) Dept. of Chemistry, University of California, Davis, One Shields Ave, Davis, 95616, (3) Department of Chemistry, Stony Brook University, Nicholls Road, Stony Brook, NY 11794-3400, (4) Department of Chemistry, SUNY Stony Brook, Stony Brook, NY 11794-3400
The excited- and ground-state photodynamics of wild-type (wt), S65T/H148D and S65T/H148E mutants of the Green Fluorescent Protein (GFP) system were characterized with femtosecond time-resolved dispersed multi-channel pump-dump-probe measurements. Discrete transient intermediates with specific spectral properties are identified to describe the evolution in the mutant variants with greater complexity than in wt-GFP. For the first time, excited- and ground state structural evolution of the chromophore is observed as non-stationary dumping kinetics. The proton transfer kinetics observed in wt-GFP is accelerated two orders of magnitude faster in S65T/H148D presumably due to a low-barrier hydrogen bond between the intrinsic chromophore and the introduced aspartate residue. Modification with glutamate residue in S65T/H148E decreases the proton transfer kinetics by 2 orders of magnitude. These results are discussed in terms of the geometry of the residues surrounding the chromophore. Dump induced signals resolve a bifurcation of the proton transfer kinetics resulting in multiple resting spots.


Optical Probes of Dynamics in Complex Environments
8:00 AM-12:00 PM, Sunday, April 6, 2008 Morial Convention Center -- Rm. 344, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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27. Hidden electronic excited state of enhanced green fluorescent protein (eGFP) by new multiplex two-photon absorption spectroscopy
PHYS 27
Haruko Hosoi, haru@riken.jp1, Shoichi Yamaguchi1, Hideaki Mizuno2, Atsushi Miyawaki2, and Tahei Tahara1. (1) Molecular Spectroscopy Laboratory, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, 351-0198, Japan, (2) Brain Science Institute, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, 351-0198
We have newly developed non-degenerate two-photon absorption (TPA) spectroscopy, which enables us to measure precise TPA spectra for a broad wavelength range, utilizing narrow-band and broad-band femtosecond pulses with multichannel detection. We applied this technique to study the electronic structure of enhanced green fluorescent protein (eGFP), which is the most widely used GFP as a fluorescent probe for bioimaging. The observed TPA spectrum is significantly blue-shifted compared with its one-photon absorption spectrum although the chromophore of eGFP has no inversion symmetry. The result indicates the existence of a 揾idden?excited state in the vicinity of the lowest excited singlet state. We conclude that this is the origin of the discrepancy between the one-photon and two-photon excitation spectra of eGFP, which is well known in the field of biology.


Optical Probes of Dynamics in Complex Environments
8:00 AM-12:00 PM, Sunday, April 6, 2008 Morial Convention Center -- Rm. 344, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

---------------------------------------------------

28. Infrared spectroscopy of tritiated water
PHYS 328
Rebecca A. Nicodemus, nicodemu@mit.edu, Lauren DeFlores, and Andrei Tokmakoff, tokmakof@MIT.EDU. Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139
Studies of water with ultrafast nonlinear infrared spectroscopy have commonly used isotopically dilute solutions, which provide a local probe of hydrogen bond dynamics. We have studied the infrared spectroscopy of tritiated water, as a step toward probing hydrogen bond switching with correlation spectroscopy between the OD and OT stretching vibrations in H2O. We report on the infrared absorption spectrum and femtosecond infrared pump-probe spectroscopy of the OT stretching vibration of HOT in H2O. We compare IR absorption line shape parameters between the three isotopes (OH:OD:OT), discussing deviations from harmonic scaling relationships in terms of electrical and mechanical anharmonicity. Comparison of the lifetimes between the three isotopes, obtained from pump-probe experiments, gives valuable information on the vibrational relaxation pathways in water.


PHYS Poster Session - Optical Probes of Dynamics in Complex Environments
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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29. Multiple exciton generation in semiconductor quantum dots and applications to third generation solar photon conversion
PHYS 210
Arthur J. Nozik, anozik@nrel.gov1, Randy J. Ellingson2, Matthew C. Beard, matthew_beard@nrel.gov3, Joseph Luther, joseph_luther@nrel.gov3, Justin C. Johnson3, Matthew D Law4, and Qing Song4. (1) NREL, 1617 Cole Blvd, Golden, CO 80401, (2) Energy Sciences, National Renewable Energy Laboratory, 1617 Cole Blvd, Golden, CO 80401, (3) Center for Basic Sciences, National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401, (4) Energy Sciences, NREL, 1617 Cole Blvd, Golden, CA 80401
In order to utilize solar power for the production of electricity and fuel on a massive scale, it will be necessary to develop solar photon conversion systems that have an appropriate combination of high efficiency (delivered watts/m2) and low capital cost ($/m2). One potential, long-term approach to high efficiency is to utilize the unique properties of quantum dot nanostructures to control the relaxation dynamics of photogenerated carriers to produce either enhanced photocurrent through efficient photogenerated electron-hole pair multiplication or enhanced photopotential through hot electron transport and transfer. To achieve these desirable effects it is necessary to understand and control the dynamics of hot electron and hole relaxation, multiple exciton generation, cooling, charge transport, and interfacial charge transfer of the photogenerated carriers with femtosecond (fs) to ns time resolution. We have been studying these fundamental dynamics in various bulk and nanoscale semiconductors (quantum dots (QDs), quantum rods/wires, and quantum wells)using fs - ns transient absorption, photoluminescence, and THz spectroscopy. Recently, we predicted the generation of more than one electron-hole pair (exciting as excitons in QDs) per absorbed photon would be an efficient process in QDs . This prediction has been confirmed by several groups using various spectroscopies over the past few years in several types of QDs. Very efficient and ultrafast multiple exciton generation (MEG) from absorbed single high energy photons has been reported in PbSe, PbS, PbTe, CdSe, InAs and Si QDs. Efficient MEG may greatly enhance the conversion efficiency of solar cells that incorporate QDs for both solar electricity and solar fuel (e.g., H2) production. Aspects of this work will be summarized and recent advances will be discussed. Various configurations for quantum dot solar cells for ultrahigh conversion efficiencies for the production of electricity and solar fuels will be presented, along with progress in developing such new types of solar cells.


Spectroscopy, Chemistry, and Imaging through Nanophotonics
8:00 AM-12:00 PM, Tuesday, April 8, 2008 Morial Convention Center -- Rm. 345, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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30. New insights into electronic structures of semiconductor nanocrystals through single-particle and ultrafast spectroscopies
PHYS 318
Victor I. Klimov, Chemistry Division, Los Alamos National Laboratory, MS-J567, Los Alamos, NM 87545
Semiconductor nanocrystals are stable, spectrally tunable chromophores with potential applications in areas such as solid-state lighting, lasing, photovoltaics, and bio-labeling. Realization of these applications requires deep understanding of electronic structures and mechanisms for light-matter interactions in nanocrystalline materials. To elucidate the mechanisms for light absorption/ emission, we apply a combination of various single-particle and ultrafast spectroscopic techniques. For example, we use single-nanocrystal photoluminescence (PL) excitation spectroscopy in conjunction with femtosecond time-resolved PL to study the structure of band-edge optical transitions and mechanism for intraband relaxation. Further, we apply single-nanocrystal magneto-PL to investigate the spin structure of emitting states and interplay between effects such as the Zeeman splitting and the long-range exchange interaction. Finally, we use photon correlation spectroscopy to conduct quantum-optical studies of single- and multiexciton states in nanocrystals.


Spectroscopy, Chemistry, and Imaging through Nanophotonics
1:20 PM-5:20 PM, Wednesday, April 9, 2008 Morial Convention Center -- Rm. 340/341, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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31. Charge transfer excitons on a crystalline organic semiconductor surface
COLL 328
Matthias Muntwiler, muntwiler@chem.umn.edu and X-Y. Zhu, zhu@chem.umn.edu. Department of Chemistry, University of Minnesota, 207 Pleasant St SE, Minneapolis, MN 55455
Organic heterojuction photovoltaic cells rely on the dissociation of excitons at donor-acceptor interfaces. Such interfacial exciton dissociation does not necessarily result in charge carriers. Due to the low dielectric constant of a typical organic semiconductor material, electrostatic interaction between an electron and a hole is sufficiently long ranged, on the order of a few to a few tens of nanometers. This leads to the formation of a weakly bound geminate pair, i.e., a charge transfer(CT) exciton, which keeps the electron and the hole in close proximity and significantly increases the possibility of charge recombination. Although such geminate pairs or CT excitons have been proposed, there is little experimental evidence of these transient species. Here, we report the observation of CT excitons on the surface of a crystalline organic semiconductor, pentacene, from femtosecond time-resolved two-photon photoemission spectroscopy. In this model system, pentacene is the electron donor and vacuum is the 揺lectron acceptor? The excited electron in a CT exciton state is bound by two contributions: electronic polarization of the pentacene surface and the electrostatic attraction from the hole. The binding energies of the two observed CT excitons are BE = 0.87 (n = 1) and 0.44 eV (n = 2), with transient lifetimes of 70 fs and 130 fs, respectively. The implications of these CT excitons in organic heterojunction photovoltaic process are discussed.


Interfacial Electron Transfer and Solar Energy Conversion: From Molecules to Nanomaterials
2:00 PM-5:40 PM, Tuesday, April 8, 2008 Morial Convention Center -- Rm. 226, Oral

Division of Colloid & Surface Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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32. nfrared pump-probe investigation of melanin vibrational relaxations
CHED 988
Aaron Massari1, Sarah A. Weinreis, saweinre@mtu.edu2, and Audrey A. Eigner, eigner@chem.umn.edu1. (1) Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, (2) Department of Chemistry, Michigan Technological University, 1400 Townsend Dr, Houghton, MI 49931
Melanin is a biological polymer of great interest to the scientific community. It is believed to play a role in the development of melanoma and Parkinson's disease, and its semiconducting properties make it a candidate for a variety of technological applications. While melanin is a substance of great importance, surprisingly little is known about its polymerization pathway and structure. The goal of this research is to compare energy dissipation properties of melanin samples prepared using a variety of techniques. The melanin samples were characterized using FTIR and studied using femtosecond infrared pump-probe spectroscopy. The pump-probe results allow for comparison of the samples' efficiency at dissipating energy. These results will indicate the extent to which different preparative techniques produce melanin polymers with similar structural characteristics.


Undergraduate Research Poster Session: Physical Chemistry
2:00 PM-4:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster

Division of Chemical Education

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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33. Photochemical investigations of diiron model complexes containing the [Fe2O(O2CR)2]2+ core
INOR 718
Jaired Tate, jaired_tate@yahoo.com, Maurice D. Edington, maurice.edington@famu.edu, and Edith N. Onyeozili. Department of Chemistry, Florida A&M University, 219 Jones Hall, Tallahassee, FL 32307
Diiron-oxo model complexes have garnered much attention in recent years due to their structural similarity to a wide array of diiron proteins. Our research focuses on gaining a comprehensive understanding of how a protein's function is mediated by active-site protein and solvent interactions; thus, studies on diiron model complexes provide a chance to study bimetallic centers in the absence of the surrounding protein. We have synthesized a series of model complexes containing a core Fe-O-Fe structure in an effort to elucidate key structural components that modulate dioxygen reactivity in these iron centers. Various optical spectroroscopic methods (i.e., photoacoustic calorimetry, UV_Vis absorption and femtosecond transient absorption spectroscopy) were employed to characterize the electronic structure and excited state characteristics of these complexes, as well as the dioxygen transport protein hemerythrin, which contains a diiron center in its active site. Results from the studies on these model complexes will be presented here.


Spectroscopy of Inorganic Systems
7:00 PM-9:00 PM, Tuesday, April 8, 2008 Morial Convention Center -- Hall A, Poster

Division of Inorganic Chemistry


The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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34. Photochemical investigations of diiron model complexes containing the [Fe2O(O2CR)2]2+ core
INOR 718
Jaired Tate, jaired_tate@yahoo.com, Maurice D. Edington, maurice.edington@famu.edu, and Edith N. Onyeozili. Department of Chemistry, Florida A&M University, 219 Jones Hall, Tallahassee, FL 32307
Diiron-oxo model complexes have garnered much attention in recent years due to their structural similarity to a wide array of diiron proteins. Our research focuses on gaining a comprehensive understanding of how a protein's function is mediated by active-site protein and solvent interactions; thus, studies on diiron model complexes provide a chance to study bimetallic centers in the absence of the surrounding protein. We have synthesized a series of model complexes containing a core Fe-O-Fe structure in an effort to elucidate key structural components that modulate dioxygen reactivity in these iron centers. Various optical spectroroscopic methods (i.e., photoacoustic calorimetry, UV_Vis absorption and femtosecond transient absorption spectroscopy) were employed to characterize the electronic structure and excited state characteristics of these complexes, as well as the dioxygen transport protein hemerythrin, which contains a diiron center in its active site. Results from the studies on these model complexes will be presented here.


Spectroscopy of Inorganic Systems
7:00 PM-9:00 PM, Tuesday, April 8, 2008 Morial Convention Center -- Hall A, Poster

Division of Inorganic Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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35. 1,2,3,4,5-Pentamethyl-cyclopentadiene dynamics probed by photoionization
PHYS 343
Fedor Rudakov, fedor_rudakov@brown.edu and Peter M. Weber, peter_weber@brown.edu. Department of Chemistry, Brown University, 324 Brook St, Providence, RI 02912
1,2,3,4,5-pentamethyl-cyclopentadiene has, upon excitation of the 1B2 state at 4.65 eV, an ultrafast curve crossing dynamics that returns the molecule to the ground state via the 2A1 state. Using time-resolved mass spectrometry and photoelectron spectroscopy we observed the 1,2,3,4,5-pentamethyl-cyclopentadiene relaxation and obtained time constants of 182(32) fs and 60(26) fs, respectively, for the curve crossings. Upon reaching the ground state surface, the molecule has ample energy to form isomers. Our experiments show conclusively, however, that no measurable structural changes take place on a femtosecond or picosecond timescale.


PHYS Poster Session - Optical Probes of Dynamics in Complex Environments
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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36. Static and time resolved vibrational sum frequency spectroscopy studies of membrane bound water
COLL 122
R. Kramer Campen, campen@amolf.nl, Avishek Ghosh, ghosh@amolf.nl, Maria Sovago, and Mischa Bonn, bonn@amolf.nl. Department of Femtophysics, FOM Institute for Atomic and Molecular Physics [AMOLF], 407 Kruislaan, 1098 SJ Amsterdam, Netherlands
Much experimental and theoretical work suggests that water participates actively in determining membrane structure. Elucidating the role of membrane associated water requires understanding its hydrogen bonding, which is reflected in the 慴onded-OH' portion of static vibrational sum frequency generation (VSFG) spectrum of lipid monolayers overlaying water. Such VSFG spectra differ for different lipid monolayers but understanding the corresponding structural differences is difficult for two reasons: the OH stretch spectrum is split by both intra- and intermolecular mode coupling and water structure evolves much more rapidly than the measurement. We address the former by taking the VSFG spectrum of the bonded OD region at the membrane/water interface, using a variety of lipids and trace HOD in H2O, and the latter by application of the newly developed femtosecond time resolved SFG to the same model membrane systems. Our results suggest that water chemical heterogeneity differs between lipids in a chemically unintuitive manner.


Structure, Property, and Function of Cell Membranes and Membrane Related Biomolecules
2:00 PM-5:20 PM, Monday, April 7, 2008 Morial Convention Center -- Rm. 229, Oral

Division of Colloid & Surface Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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37 .Investigating semiconductor-photosensitizers using N3 dye analogs
INOR 352
Sheri Lense, slense@emory.edu, Dave Stockwell, dstockw@emory.edu, Tianquan Lian, tlian@emory.edu, and Cora E. MacBeth, cora.macbeth@emory.edu. Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, GA 30322
The N3 dye has been one of the most effective and widely-used dyes for dye-sensitized solar cells. It consists of a ruthenium(II) center ligated by two thiocyanates and two 4,4'-dicarboxylic-2,2'-bipyridines. The carboxylic acid groups tether the dye to the TiO2 semiconducting nanoparticles. There is much to be learned about the role of ese tethering groups in facilitating electron transfer between the dye and semiconductor. In order to learn more about this process, analogues to the N3 dye with various spacing groups inserted between the bipyridyl groups and carbonyl have been synthesized. The synthesis and characterization of these dyes using 1H and 13C NMR, infrared and ultraviolet-visible spectroscopy, as well as mass spectrometry and electrochemistry, will be reported. Initial studies concerning electron transfer dynamics of these dyes adsorbed onto TiO2 films using femtosecond infrared spectroscopy will also be described. These studies will examine the effects of adding alkyl bridges of increasing length on electron transfer between the dye and semiconductor


Nanoscience - Characterization and Applications
7:00 PM-9:00 PM, Sunday, April 6, 2008 Morial Convention Center -- Hall A, Poster

Division of Inorganic Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008

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38. Electron transfer dynamics at the ZnO (10-10) surface
COLL 129
William A. Tisdale, tisdale@cems.umn.edu1, Matthias Muntwiler2, David J. Norris, dnorris@umn.edu1, Eray Aydil, aydil@umn.edu1, and Xiaoyang Zhu, zhu@umn.edu2. (1) Department of Chemical Engineering and Materials Science, University of Minnesota, 151 Amundson Hall, 421 Washington Ave SE, Minneapolis, MN 55455, (2) Department of Chemistry, University of Minnesota, 207 Pleasant St SE, Minneapolis, MN 55455
Recently, ZnO nanoparticle films and nanowire arrays have been used in lieu of TiO2 in dye- and quantum dot-sensitized solar cells and in hybrid organic/inorganic bulk heterojunction photovoltaic devices. The nonpolar (10-10) surface is the lowest-energy ZnO surface and constitutes the side facets of ZnO nanowires and much of the surface area of sintered ZnO nanoparticle films. Consequently, the majority of charge separation and recombination events in these devices occur at the (10-10) or equivalent surfaces. We are using time-resolved photoemission and surface nonlinear optical spectroscopies to study electron transfer dynamics at this important surface. On the clean (10-10) surface we find a continuum of defect-derived surface states extending into the band gap below the conduction band edge which may play an important role in electron transfer across this surface and in electron transport in devices featuring ZnO photoanodes. Additionally, we observe ultrafast sub-20 femtosecond cooling of hot electrons within the ZnO conduction band, suggesting that hot carrier transport may not be feasible in this material.


Interfacial Electron Transfer and Solar Energy Conversion: From Molecules to Nanomaterials
2:00 PM-6:00 PM, Monday, April 7, 2008 Morial Convention Center -- Rm. 226, Oral

Division of Colloid & Surface Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008


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39. Effect of morphology in KNb6O17 nanosheets and nanoscrolls on photocatalytic H2 evolution from water
PETR 30
Michael Sarahan, mcsarahan@ucdavis.edu1, Elizabeth C Carroll, eccarroll@ucdavis.edu1, Nigel D Browning2, Delmar S. Larsen, dlarsen@ucdavis.edu1, and Frank E. Osterloh, fosterloh@ucdavis.edu1. (1) Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616, (2) Department of Chemical Engineering and Materials Science, University of California Davis, One Shields Ave., Davis, CA 95616
Layered K4Nb6O17 has a bandgap of 3.5 eV and is a known catalyst for water splitting under UV light. Exchange of the K+ ions with propylammonium or tetrabutylammonium in water leads to nanosheets or nanoscrolls, respectively. The nanoscrolls are composed of a single niobate layer, whereas the sheets consist of two layers held electrostatically together by potassium ions. Under UV light both materials catalyze H2 evolution from water. Chemical deposition of Pt particles on the niobates increases the activity to up to 350 micromol/h (175 mg of catalyst). Similarities and differences in the two catalysts are discussed using data from TEM, HRTEM, UV/vis, fluorescence, IR, and femtosecond absorption spectroscopy.


2nd Symposium on Hydrogen from Renewable Sources and Refinery Applications
1:00 PM-5:00 PM, Sunday, April 6, 2008 Morial Convention Center -- Rm. 222, Oral

Division of Petroleum Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008


Training Workshops

Come to San Diego next summer! Attend one of our training workshops in San Diego, California during summer 2011
Del Mar Photonics has presented training workshops for customers and potential customers in the past 3 years.
Our workshops cover scientific basics, technical details and provide generous time for hands-on training.
Each workshop is a three-day seminar conducted by professional lecturer from 10am to 4pm. It includes lunch, as well as a training materials. We have also reserved two days for Q&A sessions, one-on-one system integration discussions, social networking, and San Diego sightseeing.

The following training workshops will be offered during this summer:
1. Femtosecond lasers and their applications
2. CW narrow line-width widely tunable lasers and their applications
3. Adaptive optics and wavefront sensors

4. Ultrafast (femtosecond) dynamics tools

Featured Customer

Trestles LH10-fs/CW laser system at UC Santa Cruz Center of Nanoscale Optofluidics

Del Mar Photonics offers new Trestles fs/CW laser system which can be easily switched from femtosecond mode to CW and back. Having both modes of operation in one system dramatically increase a number of applications that the laser can be used for, and makes it an ideal tool for scientific lab involved in multiple research projects.
Kaelyn Leake is a PhD student in Electrical Engineering. She graduated from Sweet Briar College with a B.S. in Engineering Sciences and Physics. Her research interests include development of nanoscale optofluidic devices and their applications. Kaelyn is the recipient of a first-year QB3 Fellowship. In this video Kaelyn talks about her experimental research in nanoscale optofluidics to be done with Trestles LH laser.

Reserve a spot in our femtosecond Ti:Sapphire training workshop in San Diego, California during summer 2011


Frequency-stabilized CW single-frequency ring Dye laser DYE-SF-007 pumped by DPSS DMPLH laser installed in the brand new group of Dr. Dajun Wang at the The Chinese University of Hong Kong.
DYE-SF-077 features exceptionally narrow generation line width, which amounts to less than 100 kHz. DYE-SF-077 sets new standard for generation line width of commercial lasers. Prior to this model, the narrowest line-width of commercial dye lasers was as broad as 500 kHz - 1 MHz. It is necessary to note that the 100-kHz line-width is achieved in DYE-SF-077 without the use of an acousto-optical modulator, which, as a rule, complicates the design and introduces additional losses. A specially designed ultra-fast PZT is used for efficient suppression of radiation frequency fluctuations in a broad frequency range. DYE-SF-077 will be used in resaerch of Ultracold polar molecules, Bose-Einstein condensate and quantum degenerate Fermi gas and High resolution spectroscopy

Other News

Optical Society of Southern California meeting at UCSD OSSC 2011-04-27
Nd:YAG laser ordered by the University of Leon, UANL, Mexico
Wedge 50 Multipass Amplifier pumped with a Darwin-527-30-M DPSS Laser ordered by Hong Kong customer
New Trestles LH10-fs/CW femtosecond+CW laser ready for delivery to the University of California Santa Cruz
Trestles femtosecond Ti:Sapphire laser delivered to North Carolina State University
Del Mar Photonics sponsor IONS (International OSA Network of Students) conference IONS-NA-2 in Tucson, Arizona IONS-NA-2 website
Best talk and best poster awards at IONS-Moscow 2010 conference sponsored by Del Mar Photonics
Watch Del Mar Photonics videos!
Del Mar Photonics is now on Twitter!

Del Mar Photonics featured components

Del Mar Photonics continuously expands its components portfolio.


 
Solar Prisms for Concentrating Photovoltaic Systems (CPV)
Solar cells made of compound semiconductors such as gallium arsenide are very expensive. Usually very small cells are installed and various means such as mirrors, lenses, prisms, etc..are used  to concentrate sunlight on the cells. Concentration photovoltaic technology (CPV) uses the solar radiation with an efficiency of 40%, double that of conventional solar cells
Del Mar Photonics design custom Concentrating Photovoltaic Systems (CPV) and supply variety of the optical components for CPV such as solar prisms shown in the picture.
 

hexagonal light pipes, optical rods


 
Axicon Lens
Axicon lens also known as conical lens or rotationally symmetric prism is widely used in different scientific research and application. Axicon can be used to convert a parallel laser beam into a ring, to create a non diffractive Bessel beam or to focus a parallel beam into long focus depth.
Del Mar Photonics supplies axicons with cone angles range from 130?to 179.5?for use with virtually any laser radiation. We manufacture and supply axicons made from BK7 glass, fused silica and other materials.

download brochure -
request a quote
Del Mar Photonics offers optical elements made of high quality synthetically grown Rutile Titanium Dioxide crystals. Rutile (TiO2) coupling prisms
Del Mar Photonics offers optical elements made of high quality synthetically grown Rutile Titanium Dioxide crystals. Rutile抯 strong birefringency, wide transmission range and good mechanical properties make it suitable for fabrication of polarizing cubes, prisms and optical isolators. Boules having high optical transmission and homogeneity are grown by proprietary method. Typical boules have 10 - 15 mm in dia. and up to 25 mm length. Optical elements sizes - from 2 x 2 x 1 mm to 12.7 x 12.7 x 12.7 mm. Laser grade polish quality is available for finished elements. So far we the largest elements that we manufactured are 12 x15 x 5 mm, in which optical axis is parallel to 15 mm edge, 5 mm is along beam path, 12 x 15 mm faces polished 20/10 S/D, one wave flatness, parallelism < 3 arc.min. (better specs. available on request).

more details - download brochure -
request a quote

Vacuum viewport

Del Mar Photonics offer a range of competitively priced UHV viewports , Conflat, ISO or KF including a variety of coatings to enhance performance. Del Mar Photonics viewports are manufactured using advanced techniques for control of special and critical processes, including 100 percent helium leak testing and x-ray measurements for metallization control. Windows Materials include: Fused silica, Quartz , Sapphire , MgF2, BaF2, CaF2, ZnSe, ZnS, Ge, Si, Pyrex. Standard Viewing diameters from .55" to 1.94 ".
Coating - a range of custom coatings can applied - which include
- Single QWOT
- Broad Band AR
- V coatings
- ITO
- DLC (Diamond like coating)

more details - request a quote

 

 

Hydrogen Thyratrons are used in such devices as radars with different power levels, high-power pulsed technical, electrophysical, medical devices and lasers. Sophisticated design and high quality ceramic-metal envelope determines long lifetime and very accurate and reliable operation of hydrogen thyratrons under wide range of environmental conditions.
Applications:
- radars
- pulsed  lasers power supplies
- medical apparatus
- electrophysical instrumentation

Triggered Three-Electrode Spark Gap Switches are ceramic-metal sealed off gas discharge trigatron-type devices with a co-axial trigger electrode. These Gas Discharge Tubes contain no mercury and, due to an advanced design, feature high reliability and a long lifetime being operating under wide range of environmental conditions.

Applications:
- pulsed installation for processing materials
- installations with plasma focus
- pulse power supplies for lasers and other pulse equipment
- medical apparatus such as lithotriptors and defibrillators
- processing systems for petroleum wells
We are looking forward to hear from you and help you with your optical and crystal components requirements. Need time to think about it? Drop us a line and we'll send you beautiful Del Mar Photonics mug (or two) so you can have a tea party with your colleagues and discuss your potential needs.

 

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Del Mar Photonics, Inc.
4119 Twilight Ridge
San Diego, CA 92130
tel: (858) 876-3133
fax: (858) 630-2376
Skype: delmarphotonics
sales@www.alaindidierweill.com
 

 

 

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