Focusing Lenses are widely used for CO2 laser application because of its low absorption at infrared wavelengths as well as its visible transmission. ZnSe has a high capacity on the shock of thermal, make it become the best optical material in high-power CO2 laser systems. But its soft material is more easily scratch and highly refraction. So there is a need highly hardness film and reduce reflection film in surface coating to protect and get a high transmittance. ZnSe Lenses is including two types, ZnSe Singlet Plano-Convex Lenses and ZnSe Singlet Positive Meniscus Lenses.
