Technique For Producing Antireflection Grating Surfaces On Dielectrics, Semiconductors And Metals

Abstract

A method of forming an antireflection rectangular-groove surface-relief grating on a lossy substrate exposed to incident waves of transverse electric or transverse magnetic or combination of polarizations and any angle of incidence in a lossless medium. The required thickness and complex refractive index of a single homogeneous layer on a lossy substrate to produce zero reflectivity is first computed using an impedance matching approach. The filling factor and groove depth of the rectangular groove surface-relief grating that is equivalent to the single homogeneous layer in the long-wavelength limit are then calculated. The surface-relief grating is then formed on the lossy substrate by reactive ion etching, electron beam lithography, or holography.