Development of chalcogenide glasses as optical materials for infrared systems

The development and use of arsenic trisulfide glass in infrared systems began in 1950. The glass was produced commercially in ton quantities by a number of companies in the US and Europe and used in NIR and MWIR systems mostly for commercial use. In the 60's, it became apparent that new optical materials capable of longer wavelength transmission would be needed for thermal imaging systems beginning to be considered. The government sponsored exploratory development programs aimed at providing selenium and tellurium containing glasses. By mid 1970's, two selenium based glass compositions had been developed and were in production in the U.S. Many tons of these two glasses have been produced and used in the 1980's, 1990's and present day for thermal imaging systems both military and commercial. The fact that only two glass compositions have been used so extensively for such a long period is due in part to the size of the effort required to identify, characterize and produce a new glass to a state where it will be considered by the optical designer for use in new systems. But new compositions may be needed to provide a glass better suited for a different application. Glasses developed by Amorphous Materials for different applications will be described.