Calcium Fluoride (CaF₂)) is commonly used for optics looking at the IR and UV spectrums and has a very low change in refractive index with wavelength. It shares similar optical properties with Barium Fluoride, although it has a transmission that is 2.5µm less into the infra-red. Calcium Fluoride is however cheaper than Barium Fluoride as the optical grade occurs naturally as opposed to BaF2 being man made.
Calcium Fluoride can be used for many applications, including vacuum ultra violet, ultra violet and infrared thermal imaging. Calcium fluoride is traditionally used in apochromatic design to reduce light dispersion in lenses, both in cameras and telescopes, and has uses in the oil and gas industry as a component in detectors and spectrometers. Calcium fluoride has low absorption and high damage threshold and as it has a low refractive index antireflective coatings are not commonly used making it an ideal choice of material for optics used in Excimer lasers are a form of ultraviolet laser used in micro-machining, eye surgery and micro-machining devices.