Manifestations of morphology-dependent resonances in Mie scattering matrices

Lorenz±Mie computations of the extinction cross-section for monodisperse spheres show the existence of a very complex structure that includes extremely narrow peaks called morphology-dependent resonances (MDRs). The width and magnitude of the peaks are highly sensitive functions of the size parameter and the refractive index of the sphere. So far the MDRs have been calculated and observed mostly for the total optical cross-sections and the scattered intensity, though it has been clear that they should also exist in the scattering matrix elements. In this paper we use modern visualization techniques to study the manifestations of MDRs in the elements of the Stokes scattering matrix and their dependence on the refractive index. We show that within MDRs, the scattering matrix elements may drastically change not only their magnitude, but also their sign. Even weak absorption inside the particles strongly modi®es and then completely destroys the polarization resonance e€ects. Ó 2000 Published by Elsevier Science Inc. All rights reserved.