Zinc Selenide (ZnSe) domes is an excellent choice for its broad wavelength range (3 µm to 16 µm), which covers MWIR and LWIR wavelength range. Zinc selienide is a chemically vapor deposition (or CVD) materials commonly used in thermal imaging and medical systems. Zinc selenide (ZnSe) windows has a high index of refraction which normally requires an anti-reflection coating to achieve high transmission. Zinc selenide is relatively soft with low scratch resistance thus not recommended for use in harsh environment. ZnSe has an excellent thermal properties which is ideal for thermally demanding environment applications.