Perturbation method to study scattering from a dielectric-chiral rough interface.

An extension of the problem of reflection from a flat dielectric-chiral interface is presented. A dielectric-chiral rough interface is assumed and scattered field is calculated using small perturbation method (SPM). Zeroth-order solution in SPM corresponds to that of a flat interface and is used to make a comparison with the earlier reported solution for a dielectric-chiral flat interface. The recursive nature of the problem has been utilized to obtain the solution to any order. First case deals with chiral grating with sinusoidal profile and diffraction efficiency is calculated. Secondly, a rough surface with the arbitrary profile is assumed and the incoherent bi-static scattering coefficient is given in terms of Gaussian roughness spectrum. Numerical results are reported for chirality parameter, permittivity, height and correlation length of the surface. Result for a dielectric rough surface is obtained by selecting chirality equal to zero. This analysis shows how much scattering differs due to chirality. [ABSTRACT FROM AUTHOR]