Shape-preserving diffusion of a high-order mode

TL;DR

This paper experimentally investigates how high-order 'elegant' modes of coherent diffusion preserve their shape, contrasting with standard modes, using atomic vapor in a storage-of-light setup to validate theoretical predictions.

Contribution

It provides the first experimental analysis of shape-preserving high-order modes in coherent diffusion, highlighting differences from optical diffraction modes.

Findings

Elegant modes maintain their shape during diffusion.

Standard modes do not preserve shape during diffusion.

Experimental results align with theoretical models.

Abstract

The close relation between the processes of paraxial diffraction and coherent diffusion is reflected in the similarity between their shape-preserving solutions, notably the Gaussian modes. Differences between these solutions enter only for high-order modes. Here we experimentally study the behavior of shape-preserving high-order modes of coherent diffusion, known as 'elegant' modes, and contrast them with the non-shape-preserving evolution of the corresponding 'standard' modes of optical diffraction. Diffusion of the light field is obtained by mapping it onto the atomic coherence field of a diffusing vapor in a storage-of-light setup. The growth of the elegant mode fits well the theoretical expectations.