Optical coating refers to the process of plating a layer (or multilayer) of metal (or medium) film on the surface of optical parts. The purpose of coating the surface of optical parts is to reduce or increase the reflection, beam splitting, color separation, filtering, polarization and other requirements of light. Commonly used coating method has vacuum coating (a physical coating) and chemical coating.

Principle of optical coating

Vacuum coating vacuum coating: vacuum coating mainly refers to the coating that needs to be carried out under higher vacuum, including vacuum ion evaporation, magnetron sputtering, MBE molecular beam epitaxy, PLD laser sputtering deposition and other coatings. There are two main types of evaporation and sputtering. The plating material will be made into the base material, and the plating material will be used as a target material or medicinal materials. The substrate is in the same vacuum as the target.

The evaporative coating is usually a heating target to evaporate the surface components in the form of free radicals or ions and deposit them on the surface of the substrate by means of film formation (scattering island structure -- trapezoidal structure -- lamellar growth), thin film.

For sputtering coatings, it is easy to understand that the target material is bombarded with electrons or high-energy lasers, and the surface components are sputtered in the form of free radicals or ions, which are deposited on the substrate surface and eventually form a film.

Common optical coating materials are as follows

Magnesium fluoride material characteristics: colorless tetragonal crystal powder, high purity, with its preparation of optical coating can improve the transmittance, no collapse point.

Silicon dioxide material features: colorless transparent crystal, high melting point, high hardness, good chemical stability. High purity, high quality Si02 coating prepared with it, good evaporation state, no collapse point. It can be divided into ULTRAVIOLET, infrared and visible light according to the requirements of use.

Zirconia material features white heavy crystalline state, with high refractive index and high temperature resistance, stable chemical properties, high purity, with its preparation of high quality zirconia coating, no collapse point.