ABSTRACT
This chapter presents the basic functionality and mode of operation of optical coatings in general and especially of reflective and antireflective coatings. Simple reflecting components can be generated by metallic mirror coatings, and sophisticated dielectric reflective layers allow the realization of high surface reflectance for broad wave bands or discrete wavelengths as required for laser mirrors with a high laser-induced damage threshold. Optical reflective coatings or mirror coatings can be realized by metallic or dielectric layers. The goal of the application of antireflective coatings is to reduce the amount of reflected light at optical interfaces and to increase transmission. In addition to reflective and antireflective coatings, a large variety of different dielectric filter coatings such as color filters or polarizers can be realized. The deposition of solid coatings from gaseous raw material, the so-called precursor gases, is referred to as chemical vapor deposition. For physical vapor deposition, the coating material is provided in solid state and vaporized by physical methods.
