Multiple Rayleigh scattering of electromagnetic waves

Abstract

Multiple scattering of polarised electromagnetic waves in diffusive media is investigated by means of radiative transfer theory. The method becomes exact in several situations of interest, such as a thick-slab experiment (slab thickness L >> mean free path $\ell >> wavelength λ)$. The present study is restricted to Rayleigh scattering. It incorporates in a natural way the dependence on the incident and detected polarisations, and takes full account of the internal reflections at the boundaries of the sample, due to the possible mismatch between the mean optical index n of the medium and that n_1 of the surroundings. Quantities of interest, such as the polarisation-dependent angle-resolved mean diffuse intensity in reflection and in transmission and the shape of the cone of enhanced backscattering, are predicted in terms of solutions to Schwarzschild-Milne equations. The latter are obtained analytically both in the absence of internal reflections and in the regime of a large index mismatch.