What is the difference between vacuum coating and optical coating in the thickness of the coating?
What is the difference between vacuum coating and optical coating in the thickness of the coating? First introduce the difference between the concepts before the two:
1. Vacuum coating refers to a method of heating metal or non-metallic materials under high vacuum conditions to evaporate and condense on the surface of the plated part (metal, semiconductor or insulator) to form a thin film, for example, vacuum aluminum plating, vacuum Chrome plating etc.
2. Optical coating refers to the process of coating a layer (or multiple layers) 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 light reflection, beam splitting, color separation, light filtering, polarization and other requirements. Commonly used coating methods include vacuum coating (a type of physical coating) and chemical coating.
The difference in film thickness:
Generally, the thickness of the electroplated metal material of the vacuum coating is about 3-5 microns. The film thickness test of the optical coating can be equipped with a film thickness tester on the top of the coating machine. In the early days, the light control test was used. Nowadays, a crystal oscillator is generally used, and the vibration frequency of the crystal oscillator is used to test the thickness of the coating. The thickness of different coatings is different.