RESONANT SCATTERING OF LIGHT BY EXCITONIC ROUGH SURFACES

The Rayleigh-Fano approach is used to study the scattering of p-polari zed light from the deterministically shaped rough surface of a semicon ductor in the vicinity of an isolated excitonic transition. Nonlocal e ffects are accounted by the Hopfield and Thomas dielectric function. A perturbative formalism is developed to calculate the amplitudes of th e scattered fields up to second order on the roughness height. Numeric al results are presented for the A(n=1) excitonic transition of CdS us ing different choices of additional boundary conditions. Comparisons a re made with the local model calculations and discussed in terms of re sonant elastic scattering. The differential reflectance spectra peaks are also shown and interpreted as surface-exciton-polariton coupling.