Structured Light in Turbulence

TL;DR

This paper reviews recent advances in using structured light for free-space optical communication through turbulence, highlighting experimental findings on optimal light types and models for improved signal robustness.

Contribution

It provides a comprehensive review combined with new experimental insights into how structured light behaves in turbulence and strategies to enhance optical communication reliability.

Findings

Certain structured light types perform better in turbulence.

Vector light behaves differently than scalar light in turbulence.

Turbulence models can be exploited for better signal processing.

Abstract

Optical communication is an integral part of the modern economy, having all but replaced electronic communication systems. Future growth in bandwidth appears to be on the horizon using structured light, encoding information into the spatial modes of light, and transmitting them down fibre and free-space, the latter crucial for addressing last mile and digitally disconnected communities. Unfortunately, patterns of light are easily distorted, and in the case of free-space optical communication, turbulence is a significant barrier. Here we review recent progress in structured light in turbulence, first with a tutorial style summary of the core concepts, before highlighting the present state-of-the-art in the field. We support our review with new experimental studies that reveal which types of structured light are best in turbulence, the behaviour of vector versus scalar light in turbulence, the trade-off of diversity and multiplexing, and how turbulence models can be exploited for enhanced optical signal processing protocols. This comprehensive treatise will be invaluable to the large communities interested in free-space optical communication with spatial modes of light.