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)²≫:1, where k_⊥ is the momentum transfer perpendicular to the surface and w is the interface width. However, for (k_⊥w)²≪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.