ABSTRACT
The functions of optical thin films are based on the optical phenomena. The optical applications of thin films have come into widespread industrial use. Thin films of absorbing and highly reflecting materials have been used widely for the optical applications, typically for instance, as astronomical reflectors. Optical thin films using nonabsorbing materials have been widely applied by utilizing the interference phenomena. Antireflection coatings can be produced on glass surfaces by combining films with suitable thicknesses and refractive indices. The group of materials utilized in thin film optics is formed by weakly absorbing substances. A combination of a metal and a nonabsorbing film is also utilized in the protective coatings, for example, of an aluminum mirror coated by a SiO layer. Evolution of the optical design is also realized for the new film having an arbitrary index range from low index to high index based on the conventional film design.
