Del Mar Photonics
CaF2 Square plane parallel window
P/N:CaF2_SPPW_12.5_12.5_0.5 - request a quote
Material: CaF2 IR optical grade
Dimensions: 12.5 x 12.5 mm (+0.0/-0.1 mm)
Thickness: 0.5mm (+/-0.05 mm)
Surface quality: 40/20 scr/dig
Parallelism: ≤ 3 arc min
Clear aperture: ≥ 90% of total dimensions
Calcium Fluoride (CaF2) prisms
Dispersion prism, IR grade CaF2, 15x15x15x10 mm - always in stock! - request a quote
Del Mar Photonics - Del Mar Photonics featured
customer Dennis Hore writes:
Our group works to characterize the interaction of biomolecules with solid surfaces. Nature designs proteins with well-defined structures
in solution. The conformation of these molecules may serve a structural purpose, or a chemical one in the case of enzymes. In order to further the progress of technologies that immobilize such molecules on synthetic surfaces (like biosensors employing enzymes), it is important to have a detailed understanding and control of the interactions of these molecules with the surface.
We use a variety of optical techniques along with computer modeling to achieve such a detailed molecular-level understanding. One of the
optical methods employed in our lab is a nonlinear technique: visible-infrared sum-frequency generation spectroscopy. Here a fixed-wavelength visible (532 nm) and tunable-infrared (2-10 microns) laser are spatially- and temporally-overlapped at the solid-solution interface under investigation. Under the right symmetry conditions, new photons are created with a frequency that corresponds to the sum of the two incident frequencies. We then characterize this new beam to work back towards the structure of the interface, which in turn provides information on the adsorbed biomolecular structure. A practical aspect of this experiment is that sample optics must be transparent in the visible, and throughout the mid-infrared region.
For this we use calcium fluoride (CaF2) prisms. Del Mar Photonics has provided high-quality prisms with custom shapes according to our drawings. One of the photos shows a close-up view of our sample cell. It is an aluminum block with internal plumbing for circulating water to maintain a constant temperature for the experiment. Inside this block there is a teflon cell that contains the analyte solution. An o-ring on the face of the cell interfaces to a CaF2 prism which forms the prism-solution (solid-liquid) interface on which the biomolecules are adsorbed. In the photo, one can see a hemi-cylindrical CaF2 prism in place. This allows the visible and infrared beams to be incident at any angle, while maintaining a horizontal plane-of-incidence.
A second experiment uses linear optical techniques to measure all 16 elements
of the 4x4 Mueller matrix of the solid-liquid interface.
This provides information on the surface roughness, thickness of the adsorbed layer, complex dielectric constant, and any anisotropy. We
employ the same sample cell design for this experiment, using either 45-deg, 60-deg, or hemicylindrical prisms. In cases where the Mueller
matrix characterization is performed for visible wavelengths only, we use fused silica prisms. For infrared-only measurements, we use zinc
selenide (ZnSe) prisms. Del Mar has been able to manufacture all shapes of prisms from CaF2, fused silica, and ZnSe according to our
To request custom quote for precision optical component please e-mail us detailed specifications and drawings or check our online store for standard components available in stock:
Del Mar Photonics, Inc.
4119 Twilight Ridge
San Diego, CA 92130
tel: (858) 876-3133
fax: (858) 630-2376
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