Chalcogenide Glasses for High Energy Laser Application

New compounding techniques were devised to prepare high purity TI no. 1173 Ge28Sb12Se60 and TI no. 20 Ge33As12Se55. The methods were based on the combination of the reactant purification and compounding steps. The goal of the program was to establish the absorption limit for the glasses and to lower the absorption at 10.6 micrometers. Glasses based on sulfur and selenium were carefully characterized to establish the interdependence between chemical composition and the magnitudes of physical parameters related to their use as infrared optical materials. The sulfur glasses selected for evaluation were from the Ge-Sb-S system. The physical properties of sulfur glasses were substantially better than those of the selenium glasses. Visible transmission was found for glasses containing 60 or more atomic percent sulfur. However, chalcogenide glasses do not appear promising as high energy CO2 laser window materials.