Diffraction from non-Gaussian rough surfaces

Most diffraction theories for random rough surfaces are based on the assumption of a Gaussian height distribution. In this paper, a diffraction theory for non-Gaussian rough surfaces is developed and the relationship between the roughness parameters and the diffraction characteristics is explored. It is shown that a non-Gaussian rough surface can dramatically alter the diffraction for (k'w) @1, where k' is the momentum transfer perpendicular to the surface and w is the interface width. However, for (k'w) !1, it is possible to determine all the roughness parameters including the interface width, lateral correlation length, and the roughness exponent without specifying the surface height distribution. @S0163-1829~97!06116-X#