Abstract:
Thallium chloride, KRS-6, and KRS-5 crystals were grown. Their bulk optical losses at wavelengths of 5-6 and 10.6$\mu m$ were $(3-5)\cdot10^{-5}$ cm${}^{-1}$ (13-22 dB/km). For KRS-6 crystals a relationship was established between the bulk absorption coefficients and the concentrations of various impurities.