Temperature anomalies of optical properties in cadmium diphosphide crystal

Abstract

The temperature dependence of refractive indices of ordinary and extraordinary rays (no, ne) in the temperature region 20-110°C for different directions in cadmium diphosphide crystal are presented in the given work. It is obtained that no and n increase with temperature growth. It is shown the thermooptical coefficient for ne depends on direction of laser beam relatively optical axis of the crystal and for no it doesn’t depend. Several anomalies in the form of steps and bends are revealed on the curves of the temperature dependence of refractive indices. The detected features are connected with the transitions between commensurate and incommensurate phases.