Third-order nonlinear femtosecond optical gating through highly scattering media

TL;DR

This paper demonstrates third-order nonlinear femtosecond optical gating to measure highly scattered light in media with extremely low transmission, advancing imaging and fundamental diffusion studies.

Contribution

It introduces a novel application of third-order nonlinear cross-correlation for time gating in highly scattering media, achieving unprecedented sensitivity.

Findings

Achieved detection at transmission factors as low as 10e-12.

First application of third-order nonlinear cross-correlation in light scattering analysis.

Enhanced capability to discriminate ballistic from diffuse light components.

Abstract

Discriminating between ballistic and diffuse components of light propagating through highly scattering media is not only important for imaging purposes but also for investigating the fundamental diffusion properties of the medium itself. Massively developed to this end over the past 20 years, nonlinear temporal gating remains limited to about 10e-10 transmission factors. Here, we report nonlinear time gated measurements of highly scattered femtosecond pulses with transmission factors as low as 10e-12. Our approach is based on third-order nonlinear cross-correlation of femtosecond pulses, a standard diagnostic used in high-power laser science, applied for the first time to the study of fundamental light scattering properties.