What is Optical Coating
1- The optical coating is composed of a thin layered medium, it is a type of optical dielectric material that propagates light through an interface.
2- The application of the optical coating began in the 1930s.
It has been widely used in many scientific optical instruments (such as lasers, optical microscopes, refracting telescopes, and interferometers)
as well as consumer devices such as binoculars, spectacles, and photographic lenses.
3- The optical coating has a smooth surface, the interface between the layers is geometrically divided;
The refractive index of the coating layer can jump at the interface, but is continuous in the coating layer;
It can be a transparent medium or an absorption medium;
It is uniform in the normal direction, or it can be uneven in the normal direction.
4- Optical coatings can be classified into: reflective, antireflective, optical filter, polarizer/polarizing , compensation/phase difference plate, alignment coating, diffusion coating/sheet, ect.
5- Optical coating manufacturing methods include thermal resistance type, electron gun type, and sputtering method.
The most common method is a thermal resistance type, vapor deposition material is put on vacuum wire or a sheet inside vacuum vapor deposition machine, in high vacuum condition, the material is vaporized and directly plated on the lens.
Since there are many materials with high melting points, it is not easy to melt and vaporize in this way. The electron gun is used to improve this disadvantage by directly striking the material with a high-pressure electron beam, which can evaporate the high-melting material by concentrating energy.
Another way is the sputtering method, in which the inert gas is ionized by high pressure, and the material is directly sputtered to the optics, and the adhesion is best in 3 methods.
Welcome to contact LPO for more Optical Coatings info!
Referenence:
1. https://en.wikipedia.org/wiki/Optical_coating
