COMPUTATION OF ELECTROMAGNETIC-WAVES DIFFRACTION BY SPECTRAL MOMENTS METHOD

In this paper, we solve, for the first time, electromagnetic wave prop agation equations in heterogeneous media using the spectral moments me thod. This numerical method, first developed in condensed matter physi cs, was recently successfully applied to acoustic waves propagation si mulation in geophysics. The method requires the introduction of an aux iliary density function, which can be calculated by the moments techni que, This allows computation of the Green's function of the whole syst em as a continued fraction in time Fourier domain, The coefficients of the continued fraction are computed directly from the dynamics matrix obtained by discretization of wave propagation equations and from the sources and receivers, We illustrate this method through the study of a plane wave diffraction by a slit in two-dimensional (2-D) media and by a rectangular aperture in three-dimensional (3-D) media, Compariso n with analytical results obtained with the Kirchhoff theory shows tha t this method is a very powerful tool to solve propagation equations i n heterogeneous media, Last, we present a brief comparison with other computing methods.