NEW FAR INFRARED WINDOW MATERIALS - FROM ZINC-SULFIDE THROUGH CALCIUM LANTHANUM SULFIDE TO DIAMOND

Zinc sulphide is an excellent window material for many current airborne 8-12-mu-m infrared optical systems. However future systems will require a much more robust material and the considerable success which has been made towards providing such a material is described. The physical properties of existing window materials such as germanium, gallium arsenide, zinc selenide, zinc sulphide, and a zinc sulphide/zinc selenide laminate are compared with an emerging material, calcium lanthanum sulphide, and a potentially available material, diamond.