Optical Crystals such as CaF₂, BaF₂, MgF₂, LiF, Nacl, KCL, KBR are widely used in IR optics and UV optics. High transparency and low loss optical windows, prisms, lenses, acromatic lenses and parallel planes have been fabricated in these optical materials. These crystals are applied to entire optical wavelength range from vacuum ultraviolet (0.11um) to far infrared (40um).

Some doped fluoride crystals like LiF:Mg,Ti or CaF2: Dy are radiation detectors and efficient TL dosimeters mainly for higher energy radiation. Most solidstate dosimeters are based on effects of thermoluminescence (TL) and more recently also on methods of optically stimulated luminescence (OSL) and photo-transferred TL (PTTL).

It should also be noted that the application of monochromatic VUV radiation enables the evaluation of the photon energy which is most efficient for the formation of defects and the excitation of TL.