Optical properties of alkali halide and thallium halide single crystals

Abstract

The large single crystals of alkali halide and thallium halide were produced by Bridgman-Stockbarger method. The absorption spectra of KRS-5, TlBr and TlCl with the several thickness near the short edge were measured and compared with the results of various investigators. Although the exciton peak was not detected, the impurity band of thallium compound and the red shift of short edge were found. Also, their reflectance spectra of NaF, TlCl and KRS-5 in the far infrared region were measured. And these results were analysed referring to the Drude's dispersion formula, thus the damping constants of these crystals at room temperature were estimated to be 0.045 for NaF, 0.15 for TlCl, and 0.18 for NaF respectively.