Universal crosstalk of twisted light in random media

TL;DR

This paper demonstrates that the crosstalk between twisted light modes in complex media depends universally on a single ratio of medium and beam properties, with both numerical and experimental validation.

Contribution

It introduces a universal function governing OAM mode coupling in random media, applicable even under strong intensity fluctuations.

Findings

Numerical and experimental evidence of the universal crosstalk function.

Crosstalk depends solely on the ratio of medium and beam correlation lengths.

Applicable to complex media like Earth's atmosphere.

Abstract

Structured light offers wider bandwidths and higher security for communication. However, propagation through complex random media, such as the Earth's atmosphere, typically induces intermodal crosstalk. We show numerically and experimentally that coupling of photonic orbital angular momentum (OAM) modes is governed by a universal function of a single parameter -- the ratio between the random medium's and the beam's transverse correlation lengths, even in the regime of pronounced intensity fluctuations.