Enhanced transmission through rough surfaces with an even profile

Abstract

One of the most interesting phenomena associated with the scattering of light from a randomly rough surface is that of enhanced backscattering. Enhanced backscattering refers to the presence of a well-defined peak in the angular distribution of the intensity of the incoherent component of the light scattered from such a surface. This peak occurs in the retroreflection direction. Not all of the manifestations of weak localization in the interaction of light with random metallic grating are in reflection. It was recently shown that the angular distribution of the intensity of the incoherent component of polarized light transmitted through a thin metal film in vacuum, whose illuminated surface is randomly rough and whose back surface is planar, displays a well-defined peak in the transmission direction that is directly opposite to the direction of specular reflection of the incident light (the antispecular direction).1 The enhanced transmission effect, which is manifested as a narrow peak in the angular distribution of the intensity of diffuse scattered light in the antispecular direction, has recently been investigated experimentally. This peak is an analogue of enhanced backscattering in the transmission of light through a randomly rough surface. Several surfaces were fabricated and tested, such as one-dimensional randomly rough metal and dielectric surfaces with an even profile. A fully automatic, bidirectional reflectometer was used to measure the enhanced transmission under illumination of a He-Ne laser. The results are compared with numerical calculations.