Calcium fluoride (_CaF2) has a broad transmission band in the wavelength range between 0.12 µm and 10.5 µm. Even at a wavelength of 160 nm, the transmission percentage is over 80% (see spectral properties). The material is only very weakly birefringent. Calcium fluoride has good mechanical and thermal properties, resulting in good machinability of the material. Together with the broad transmission band, these properties make _CaF2 a versatile material that, after lithium fluoride, is most frequently used for VUV optics.

Crystals of calcium fluoride are grown using the Czochralski or Bridgman method. The material is processed in several qualities (IR, UV) and is available as both monocrystalline and polycrystalline material.

Calcium fluoride is used to produce optical windows, prisms, lenses and other optical elements.