title: Electromagnetic scattering by fully ordered and quasi-random rigid particulate samples.
abstract: In this paper we have analyzed circumstances under which a rigid particulate sample can behave optically as a true discrete random medium consisting of particles randomly moving relative to each other during measurement. To this end, we applied the numerically exact superposition T-matrix method to model far-field scattering characteristics of fully ordered and quasi-randomly arranged rigid multiparticle groups in fixed and random orientations. We have shown that, in and of itself, averaging optical observables over movements of a rigid sample as a whole is insufficient unless it is combined with a quasi-random arrangement of the constituent particles in the sample. Otherwise, certain scattering effects typical of discrete random media (including some manifestations of coherent backscattering) may not be accurately replicated.
authors.forename: Michael I
authors.initials: MI
authors.lastname: Mishchenko
authors.forename: Janna M
authors.initials: JM
authors.lastname: Dlugach
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Mackowski