Ideal for excimer laser applications
Low absorption and high damage threshold
Transparent in UV, Visible, and IR
<1 arc-minute parallelism
Low chromatic aberration compared to other IR materials
Calcium Fluoride optical windows are transparent from 180 nm to 8 µm, making them ideal for applications such as spectroscopy or fluorescence imaging in the UV, visible, and IR wavelengths.
Calcium Fluoride has both high average transmission and low chromatic aberration compared to most IR materials. Unlike Germanium and Silicon, it is also transparent in the UV and Visible wavelength ranges, making it suitable for applications such as fluorescence imaging, or spectroscopy where operation over many wavelength bands is essential. Other application examples include use in femtosecond IR systems due to low group velocity dispersion in the IR) and use in excimer laser systems due to low UV absorption and high damage threshold).
The refractive index of Calcium Fluoride is remarkably stable vs wavelength. Visible chromatic aberration is extremely low with an Abbe Number of 95.31 compared to N-BK7 at 64.17, which means that this material is great for imaging applications. In the infrared region CaF2 is an excellent material to use in ultrafast experiments as it has the lowest group velocity dispersion (GVD) of any IR Material at 1.77 fs2/mm. This is half the GVD of Magnesium fluoride and orders of magnitude lower than Germanium or Silicon.
| CAW | 10CF | |
|---|---|---|
| Material | CaF2 (Vacuum UV Grade) | |
| Thickness | See Ordering Info Table | |
| Size tolerance | +0.0/-0.1 mm | ±0.20 mm |
| Surface Quality | 40-20 scratch-dig | |
| Surface Flatness | λ/2 @ 632.8 nm | λ/20 @ 10.6 µm |
| Parallelism | < 1 arc minute | < 3 arc minute |
| Clear Aperture | 90% of central diameter | Central 85% of diameter |
| Refractive Index | 1.38 @ 620 nm | |
| Hardness (Knoop) | 158 kg mm-2 | |
| Young\'s modulus | 7.6 x 1011 N m-2 | |
| Thermal Limit | 10 W m-1 K-1 @ 273 K | |
| Thermal expansion coefficient | 18.9 x 10-6 K-1 @ 300K | |