The coating technology used by the optical pvd coating machine is generally known as optical coating, and the common method of optical coating technology is to coat the film on the glass substrate by vacuum sputtering, and the optical coating is usually used to control the reflectivity and transmission of the incident light beam on the substrate to meet different needs. In order to eliminate the reflection loss on the surface of the optical component and improve the image quality, one or more transparent dielectric films are coated, called anti-reflection films or anti-reflection films.

With the development of laser technology, different requirements are put forward for the reflectance and transmittance of thin films, which promotes the development of multi-layer high-reflection films and wideband anti-reflection films. For a variety of application needs, the use of highly reflective film to manufacture polarization reflection film, color separation film, cold light film, interference filter and so on.
After coating the surface of the optical component, the optical coating reflects and transmits several times on the coating, resulting in multi-beam interference. Different intensity distributions can be obtained by controlling the refractive index and thickness of the coating. This is the basic principle of interference coating.
The optical properties of the coating, such as refractive index, absorptivity and laser damage threshold, depend mainly on the microstructure of the coating. Film material, residual air pressure and substrate temperature may affect the microstructure of the film. If the mobility of the vapor-deposited atoms on the surface of the substrate is low, the coating will contain micropores. When the film is exposed to humid air, these holes are gradually filled with water vapor. Like a cylindrical mirror.