Exact Results of the Vector Theory of Coherent Backscattering from Discrete Random Media: An Overview

Abstract

Coherent backscattering of light by discrete random media, otherwise known as weak photon localization, is a remarkable optical phenomenon caused by constructive interference of waves propagating along the same light-scattering paths but in opposite directions. A well-known manifestation of coherent backscattering is an intensity peak centered at exactly the backscattering direction. It also has been established that when the incident beam is unpolarized then the coherent backscattering intensity peak can be accompanied by a sharp asymmetric peak of negative polarization with a minimum centered at a very small phase angle. It has been suggested that coherent backscattering could be a contributor to some effects observed for solar system bodies in visible light and at radiowave frequencies [1–4]. However, accurate theoretical computations of weak photon localization based on first physical principles are difficult and have been used in analyses of planetary observations in only a handful of publications. This chapter briefly discusses manifestations of coherent backscattering and reviews the exact theory of this phenomenon and its applications to analyses of laboratory data and remote-sensing observations.