Sapphire optical window film is widely used, it is used to replace other optical materials, optical components, through the infrared optical window, and is widely used in infrared and far infrared military equipment, such as: used in night vision infrared and far infrared sight , Night vision cameras and other instruments and satellites, space technology instruments and instruments used as high power lasers, various optical prisms, optical windows, UV and IR windows and lenses, low temperature experimental observation port, used in aerospace High precision instruments and so on.