Probing minimal scattering events in enhanced backscattering of light using low-coherence induced dephasing

TL;DR

This paper demonstrates that low-coherence illumination can isolate minimal scattering events in enhanced backscattering of light, providing experimental evidence that double scattering is the fundamental process in this phenomenon.

Contribution

It introduces a novel low-coherence technique to control and analyze scattering events in enhanced backscattering, confirming the minimal scattering order experimentally.

Findings

Minimum scattering events in EBS are double scattering.

Low-coherence illumination isolates single scattering contributions.

Potential applications in characterizing weakly scattering media.

Abstract

We exploit low spatial coherence illumination to dephase time-reversed partial waves outside its finite coherence area, which virtually creates a controllable coherence volume and isolates the minimal number of scattering events from higher order scattering in enhanced backscattering (EBS, also known as coherent backscattering) of light. We report the first experimental evidence that the minimum number of scattering events in EBS is double scattering in discrete random media, which has been hypothesized since the first observation of EBS of light. We discuss several unique characteristics and potential applications of low-coherence EBS in weakly scattering random media.