THE TELLURIUM HALIDE GLASSES

The reaction of tellurium with the halogens Cl, Br and I leads to a new family of halide glasses which are structurally related to Se. These chain-like materials are characterized by a broad optical window lying from 1 to 13 μm or 1 to 20 μm, depending on the weight of the halogen. When combined with S or specially Se, many of these new IR glasses exhibit a strong resistance towards devitrification and water corrosion. Infrared optical fibers have been prepared from these so-called TeX glasses. The position and the dependence of the multiphonon edge as well as the bandgap have been investigated by measuring the attenuation spectra. It has been shown that these glasses exhibit low optical losses in the 8-12 μm atmospheric window. Thin layers of TeX glasses have been deposited by sputtering on silica or fluoride glass substrates, and antireflection coatings deposited on bulk TeX glasses allow the reduction of optical losses by reflection. © 1990.