Light scattering by randomly rough isotropic dielectric surfaces

An experimental investigation of the angular distribution of the light scat tered by randomly rough, two-dimensional, isotropic dielectric surfaces is presented. The surfaces, whose profiles constitute good approximations to G aussian random processes with Gaussian correlation functions, are fabricate d in a photoresist and characterized by means of a mechanical profilometer. The substrates employed in the fabrication of the samples consist of thick parallel plates of filter glass that absorb the incident light and whose r efractive index is close to that of the photoresist. This allows us to appr oximate experimentally a situation in which the light is scattered by a ran domly rough interface between two semi-infinite dielectric media, illuminat ed from the air side. The results display features that can be attributed t o multiple scattering. In particular, significant amounts of cross-polarize d scattered light, as well as an enhanced backscattering peak, were observe d in the scattering measurements.