Optimization of chalcogenide glass in the As–Se–S system for automotive applications

Infrared transmitting glasses in the As–Se–S system have been optimized by taking in account specifications for automotive application. The As2Se3 glass has been chosen as the starting composition and sulfur is introduced in order to improve some optical and mechanical properties. As expected, the Sulfur introduction decreases the refractive index as well as its change as function of temperature. The relationship between the refractive index and the glass composition has been established. The thermal coefficient of refractive index for sulfur containing glasses can be lower than 4 × 10−5 K−1, which is considerably lower than that of germanium, the most used infrared transmitting materials. Influence of sulfur on other properties has also been studied.