Temperature dependence of the diffraction efficiency of circular polarization gratings made by liquid crystal molecules with anisotropic absorption

Abstract

Since liquid crystal molecules exhibit anisotropic absorption in the infrared region, there is concern about changes in the diffraction properties of polarization gratings (PGs) made of liquid crystals. In this study, we investigated the theory of the diffraction efficiency of the circular PGs with circularly polarized diffraction characteristics when they have anisotropic absorption. We found that the separation function of the circularly polarized light was maintained even in the presence of anisotropic absorption. The usefulness of this theory was discussed with experimental results of the temperature dependence of the diffraction efficiency of a circular PG at 10.2 μm.