Exploiting breakdown of the similarity relation for diffuse light transport: simultaneous retrieval of scattering anisotropy and diffusion constant

TL;DR

This paper demonstrates that time-resolved detection of transmitted diffuse light, combined with Monte Carlo simulations, enables simultaneous retrieval of scattering anisotropy and diffusion constant even in multiple scattering regimes.

Contribution

It introduces a novel method leveraging the limited validity of the diffusion approximation to extract microscopic scattering parameters from deep multiple scattering regimes.

Findings

Time-resolved detection allows parameter retrieval in multiple scattering regimes.

Monte Carlo simulations effectively match experimental data for parameter estimation.

Simultaneous assessment of anisotropy and diffusion constant is feasible deep into multiple scattering.

Abstract

As manifested in the similarity relation of diffuse light transport, it is difficult to assess single scattering characteristics from multiply scattered light. We take advantage of the limited validity of the diffusion approximation of light transport and demonstrate, experimentally and numerically, that even deep into the multiple scattering regime, time-resolved detection of transmitted light allows simultaneous assessment of both single scattering anisotropy and scattering mean free path, and therefore also macroscopic parameters like the diffusion constant and the transport mean free path. This is achieved via careful assessment of early light and matching against Monte Carlo simulations of radiative transfer.