Being applied to Germanium or Silicon windows and lenses DLC provides BBAR performance coupled with excellent protection of outer optical surfaces from negative influences of the environment (humidity, dust, atmospheric precipitations) and stays inert to mechanical strikes, thermal shock, acids, salts, solvents and other chemical reagents. It consists of carbon and hydrogen. Field of application is military devices and outside thermal cameras. Sometimes it’s better to have window and lenses coated DLC+BBAR. DLC coatings can be applied to Ge and Si substrates of sizes as big as 320mm in diameter.