Coherence of a light beam through an optically dense turbid layer.

A light beam propagating through a turbid medium (e.g., aerosol) can be severely attenuated by scattering losses and still retain coherence over distances comparable to particle diameters. An expression for the two-detector mutual-coherence function is rederived by means of approximations clarified by a physical model. Its spatial and temporal properties are further examined by means of a simplified physical aerosol model leading to tractable mathematical analysis.