Random matrix description of dynamically backscattered coherent waves propagating in a wide-field-illuminated random medium

Abstract

The wave propagation in a random medium plays a critical role in optics and quantum physics. Multiple scattering of a coherent wave in a random medium determines the transport procedure. Brownian motions of scatterers perturb each propagation trajectory and form dynamic speckle patterns in the backscattered direction. In this study, we applied the random matrix theory to investigate the eigenvalue density of the backscattered intensity matrix. We find that the dynamic speckle patterns can be utilized to decouple the single and multiple backscattered components. The Wishart random matrix of the multiple scattering component is well described by the Marčenko–Pastur law, while the single scattering part has a low-rank characteristic. We, therefore, propose a strategy for estimating the first and second order moments of single and multiple scattering components, respectively, based on the Marčenko–Pastur law and trace analysis. Electric field Monte Carlo simulation and in vivo experiments demonstrate its potential applications in hidden absorbing object detection and blood flow imaging. Our method can be applied to other coherent domain elastic scattering phenomena for wide-field propagation of microwave, ultrasound, etc.