Azimuthal asymmetry of the coherent backscattering cone: Theoretical results

The azimuthal asymmetry of the polarized backscattering cone and the intimately related polarization opposition effect (POE) are corollaries of the theory of coherent backscattering (CB) valid in the asymptotic limit of very small particle packing density. In this paper we use numerically exact solutions of the Maxwell equations to study the evolution of these and other manifestations of CB as the packing density in a multiparticle group increases from zero to values typical of actual particle suspensions and particulate surfaces. Our results reveal a remarkable robustness of virtually all effects predicted by the low-density concept of CB and allow us to conclude that the azimuthal asymmetry and POE observed in the laboratory for densely packed discrete random media are indeed caused by CB.