Optical properties of multilayer antireflection coating systems on a ferroelectric base

Antireflection coatings have had the greatest impact on optics. Characteristics of the ferroelectric based multilayered antireflection coating systems are investigated. Multilayer antireflection coatings consisting of insulator thin films have been modeled in the region between 400 nm and 800 nm visible bands of electromagnetic spectrum to reduce reflectance from ferroelectric based substrate. In this type of antireflection coating we can regulate the optical properties of system by external electric or thermal field. In order to design and simulate the normal incidence wideband visible multilayer AR coatings we have developed a Fortran software program based upon Fresnell equations. It is used different types of layers which are two-different materials like ZnSe and ZrO2 for even-folded multilayer (two-, four-, six-, eight-, ten-, and twelve-layer) antireflection coatings, and ZnSe, ZrO2, and Ag2AsS3 for odd folded (three-, six-, nine-, and twelve-layer). It is used ferroelectric material, LiNbO3 as the substrate. The optical thicknesses of each layer are equal to a quarter-wave thick at a certain wavelength.