LIGHT-SCATTERING BY A REENTRANT FRACTAL SURFACE

Recently, rigorous numerical techniques for treating light scattering problems with one-dimensional rough surfaces have been developed. In t heir usual formulation, these techniques are based on the solution of two coupled integral equations and are applicable only to surfaces who se profiles can be described by single-valued functions of a coordinat e in the mean plane of the surface; In this paper we extend the applic ability of the integral equation method to surfaces with multivalued p rofiles. A procedure for finding a parametric description of a given p rofile is described, and the scattering equations are established with in the framework of this formalism. We then present some results of li ght scattering from a sequence of one-dimensional flat surfaces with d efects in the form of triadic Koch curves. Beyond a certain order of t he prefractal, the scattering patterns become stationary (within the n umerical accuracy of the method). It can then be argued that the resul ts obtained correspond to a surface with a fractal structure. These co nstitute, to our knowledge, the first rigorous calculations of light s cattering from a reentrant fractal surface. (C) 1997 Optical Society o f America.