Measurement of transport mean free path of light in thin systems

TL;DR

This study measures the transport mean free path of light in thin systems using a novel directional probing method, enabling analysis of samples previously difficult to investigate.

Contribution

It introduces a new experimental approach combining amplified spontaneous emission with simulations to accurately determine light diffusion properties in thin samples.

Findings

Accurate measurement of transport mean free path in thin systems.

Validation of the method through comparison with simulations.

Enabling analysis of previously inaccessible sample types.

Abstract

We extensively investigate in-plane light diffusion in systems with thickness larger than but comparable with the transport mean free path. By exploiting amplified spontaneous emission from dye molecules placed in the same holder of the sample, we obtain a directional probe beam precisely aligned to the sample plane. By comparing spatial intensity distribution of laterally leaking photons with predictions from random walk simulations, we extract accurate values of transport mean free path, opening the way to the investigation of a previously inaccessible kind of samples.