Localization effects in the elastic scattering of light from a randomly rough surface

The diffuse scattering of light from a randomly rough surface is calculated for the case in which this scattering is accompanied by the resonant excitation of surface polaritons. In these calculations the light is incident normally upon the plane of the mean surface. The diffuse scattering is shown to exhibit intensity maxima in the antispecular direction, owing to the localization of surface polaritons. These maxima are smaller for s to s, s to p, and p to s scattering than for p to p scattering. Two calculations are presented: one in which dielectric losses are large compared with the attenuation of surface polaritons that is due to the roughness and one in which dielectric losses are small compared with other mechanisms of attenuation. Both calculations proceed by diagrammatic expansions that take into account the diagrams responsible for localization phenomena. The surface roughness is considered to be weak enough that such perturbation techniques are applicable.