Photon delocalization transition in dimensional crossover in layered media

TL;DR

This paper investigates how optical wave propagation in layered media transitions from localized to diffusive behavior as the system's dimensionality changes from one to three dimensions, influenced by layer thickness nonuniformity.

Contribution

It introduces the concept of a crossover point in layered media where wave behavior shifts from localization to diffusion based on the lateral spread and coherence length.

Findings

Crossover occurs when lateral spread equals transverse coherence length.

Wave behavior transitions from localization to diffusion with increasing dimensionality.

The study provides a criterion for the localization-diffusion transition in layered structures.

Abstract

We report a crossover in optical propagation in random layered media from localization towards diffusion as the interaction of the wave with the sample is transformed from one to three-dimensional due to nonuniformity in the layer thickness. The crossover occurs at the point that the lateral spread of the wave equals the transverse coherence length in the transmitted speckle pattern.