Design of high efficiency multilayer antireflection coatings for visible and infrared substrates

Abstract

Multilayer antireflection coatings have been designed invisible region (400-700nm) and IR (3 - 5pm) bands to reducereflectance of glass, germanium (Ge) and silicon (Si) substrates.The Reflectance of bare glass substrate is around (4.2%) persurface, whereas for Ge (36%), Si (30%).These values arereduced reasonably by the application of multilayer films.Starting from a single, double and multilayer. The layers havebeen added systematically to reduce the reflectance by theaddition of each layer. The designed layers are enhanced fortheir performance by varying their thickness and refractiveindices. The results shown that the proposed structures are veryeffective in reducing the reflectance for all the substrates in twospectra regions.