Temperature dependence of optical anisotropy parameter of CaF 2 , BaF 2 and SrF 2 materials

Abstract Thermally induced depolarization in undoped CaF2, BaF2 and SrF2 crystals was measured. The obtained results were used to determine temperature dependence of the optical anisotropy parameter ξ of these materials in the 80–300 K range. Temperature dependence of the orientation of crystallographic axes corresponding to the “zero depolarization” orientation was found. It was revealed that thermally induced depolarization in the studied materials cooled to 80 K reduces by more than 100 times, with changes in the parameter ξ being 5.8%, 6.4% and 28%, respectively.