An Investigation of Material Properties for a Selection of Chalcogenide Glasses for Precision Glass Molding

The growing demand for lower cost infrared sensors and cameras has focused attention on the need for low cost optics for the long wave and mid-wave infrared region. The combination of chalcogenide glasses and Precision Glass Molding (PGM) is the enabling technology for low cost infrared optics. The lack of detailed material properties data has limited its acceptance in the commercial market, but increased demand and recent cost reductions in infrared sensors has focused additional attention onto these materials as a cost driver for infrared systems. This investigation reviews the material performance and repeatability for a number of different chalcogenide glasses. Material properties including composition, glass transition temperature (T-g), coefficient of thermal expansion (CTE), index of refraction, transmission and change in index over temperature (dn/dT) are explored. Specific attention is given toward glasses that achieve high yields during precision glass molding and are candidates for commercial success.