Propagation of coherent waves in elastically scattering media

TL;DR

This paper introduces a comprehensive method for analyzing speckle pattern correlations and sensitivities of coherent waves in various disordered media, bridging diffusive and ballistic wave regimes.

Contribution

It develops a unified approach similar to Boltzmann-Langevin theory for calculating statistical properties of speckle patterns in complex scattering environments.

Findings

Calculated wave intensity correlation functions.

Analyzed sensitivity to wave frequency and incident angle.

Applicable across diffusive and ballistic scattering regimes.

Abstract

A general method for calculating statistical properties of speckle patterns of coherent waves propagating in disordered media is developed. It allows one to calculate speckle pattern correlations in space, as well as their sensitivity to external parameters. This method, which is similar to the Boltzmann-Langevin approach for the calculation of classical fluctuations, applies for a wide range of systems: From cases where the ray propagation is diffusive to the regime where the rays experience only small angle scattering. The latter case comprises the regime of directed waves where rays propagate ballistically in space while their directions diffuse. We demonstrate the applicability of the method by calculating the correlation function of the wave intensity and its sensitivity to the wave frequency and the angle of incidence of the incoming wave.