Optics are finished with a high-quality PVD coating to protect surfaces against environmental influences or to improve their optical properties.
The applied layer thicknesses are between a few nanometers and a few micrometers. A distinction is made between metallic coatings and dielectric coatings, whereby dielectric coatings are particularly suitable for laser systems due to their low absorption.
The application of optical coatings is a complex process. Important parameters are the refractive index, the temperature of the substrate, the vacuum and the coating speed. The materials are then selected based on the optical, mechanical and chemical properties.