Optical

Diamond is unmatched in being transparent from near the ultra-violet cut-off at 225 nm to beyond a wavelength of 100µm, including the atmospheric infrared transmission bands.

The use of diamond materials in optical applications such as infrared laser windows, was, for a long time, restricted by the size and cost of natural diamond. The use of CVD diamond is an economic alternative to zinc selenide (ZnSe) because of its hardness and high thermal conductivity.