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

Multilayer antireflection coatings have been designed in visible region (400-700nm) and IR (3 - 5pm) bands to reduce reflectance of glass, germanium (Ge) and silicon (Si) substrates. The Reflectance of bare glass substrate is around (4.2%) per surface, whereas for Ge (36%), Si (30%).These values are reduced reasonably by the application of multilayer films. Starting from a single, double and multilayer. The layers have been added systematically to reduce the reflectance by the addition of each layer. The designed layers are enhanced for their performance by varying their thickness and refractive indices. The results shown that the proposed structures are very effective in reducing the reflectance for all the substrates in two spectra regions.