OXYCHLORIDE GLASSES FOR INFRARED TRANSMISSION

Heavy metal oxychloride glasses can be prepared with good IR transmission out to 8.8 microns. Scattering losses will prohibit their use for long distance transmission, compared to fluorozirconates, but they have some attractions in terms of improved thermal stability. Tc-Tg gaps of up to 149-degrees-C can be achieved and compositions containing less than approximately 30 at % Cl appear to be stable in air. The thermal and chemical properties of ternary glasses based on the Sb2O3-PbCl2-ZnCl2 system are discussed in relation to composition