Calcium fluoride CaF2 is commonly used as a window material for both infrared and ultraviolet wavelengths, since it is transparent in these regions (about 0.15mm to 9mm) and exhibits extremely weak birefringence. Furthermore the material is fairly inert chemically so that these windows are not attacked. Nevertheless, at wavelengths as low as 157nm, which are interesting to semiconductor manufacturers, the birefringence of calcium fluoride exceeds tolerable limits.
Fluorides are toxic to humans, however CaF2 is considered relatively harmless due to its extreme insolubility
We provide artificially-crystallized calcium fluoride components available in IR grade and UV Grade. The cost of UV grade is much expensive than IR grade.