Impact of wave polarization on long-range intensity correlations in a disordered medium

Abstract

We present a theory of long-range intensity correlations in phase-coherent transport of polarized light through a disordered medium. Diagrammatic calculations of the intensity correlation function are performed beyond the scalar wave approximation. The correlations between the cross-polarized fields are shown to result in the dependence of mesoscopic intensity fluctuations on the polarization of the incident light. The intensity correlation function is represented as a sum of the contributions from the scalar mode and the basic modes of circular and linear polarization. The calculations, as applied to media with large scattering inhomogeneities, are carried out for diffusive transport and for small-angle multiple scattering of light. Each polarization contribution to the variance of relative transmission fluctuations is shown not to be a self-averaging quantity and tends to a nonvanishing value as the sample thickness increases. This value is proportional to the length of polarization decay in the medium and can be measured by varying the initial polarization of light.