ZnSe is used for optical windows, lenses, mirrors, prisms and optical blanks, plates, disks, sheets, slabs particularly for infrared applications Zinc Selenide (ZnSe) — transparent in wide spectral range from yellow (visible) to far IR. ZnSe material is a chemically inert, non-hygroscopic and highly pure product that is very effective in many optical applications due to its extremely low bulk losses, high resistance to thermal shock and stability in virtually all environments, easily machined.