CaF2 Window
Calcium fluoride is often used in spectroscopic windows and lenses due to its high transmission from 250nm to 7μm. Its low absorption and high damage threshold makes it a popular choice for excimer laser optics. Calcium fluoride’s low index or refraction allows it to be used without an anti-reflective coating. The Knoop hardness of calcium fluoride is 158.3. TECHSPEC® Calcium Fluoride (CaF2) Windows manufactured from vacuum UV grade calcium fluoride are commonly found in cryogenically cooled thermal imaging systems.
Advantages
1 ) Low Absorption, High Transmission UV Grade Calcium Fluoride
2 ) Ideal for Applications Ranging from 250nm – 7μm
3 ) Low Index of Refraction
Specifications
1 ) Diameter: 3~375mm
2 ) Diameter Tolerance: +/-0.2mm
3 ) Thickness Tolerance: +/-0.03mm
4 ) Aperture: >90%
5 ) Surface Quality: 80/50~10/5 (S/D)
6 ) Parallelism: <1 arc minute
7 ) Chamfer: 0.3-0.5mmx45°
Optical Properties
Transmission Range | 0.13 to 10 micron |
Refractive Index | 1.39908 at 5 micron |
Refractive Loss | 5.4% at 5 micron |
Crystal/Class Structure | Cubic CsCl, Pm3m |
Cleavage Plane | No cleavage planes |
Thermal Properties
Thermal Expansion | 47.9×10-6 /℃ at 273K |
Thermal Conductivity | 9.71 W m-1K-1 |
Melting Point | 1360 ℃ |
Specific Heat Capacity | 854 J Kg-1K-1 |
Mechanical Properties
Density | 3.18 g/cc |
Hardness(Knoop) | 158.3 (100) with 500g indenter |
Youngs Modulus | 75.8 GPa |
Shear Modulus | 33.77 GPa |
Bulk Modulus | 82.71 GPa |
Poisson Ratio | 0.26 |
Elastic Limit | C11=164 C12=53 C44=33.7 |
Molecular Weight | 78.08 |
Chemical Properties
Solubility | 0.0017 g/100g water at 20℃ |