Annular beams for reliable intersatellite optical communications

TL;DR

This paper experimentally demonstrates the use of annular beams generated by spiral phase plates to improve power efficiency in intersatellite optical communications, addressing beam pointing jitter issues.

Contribution

It introduces a practical method to generate higher-order annular beams using spiral phase plates and evaluates their effectiveness in space communication links.

Findings

Annular beams can be reliably generated with acceptable errors and losses.

Superpositions of annular beams can save approximately 20% power compared to Gaussian beams.

The approach is viable for improving intersatellite optical communication performance.

Abstract

Free-space optical communications (FSOC) are a key enabling technology for future high-capacity space-based networks. Particularly, the backbone of global communication relies on intersatellite optical links. In a previous study, the authors proposed a method to mitigate the impact of transmitter pointing jitter by using a superposition of orthogonally polarized Gaussian and higher-order Laguerre-Gaussian (LG) beams. In this study, we experimentally characterize the proposed system using a spiral phase plate (SPP) to generate higher-order annular beams. We demonstrate that such superpositions can be reliably generated in a realistic optical setup, quantify the associated beam-shaping errors and losses, and assess their impact on intersatellite optical communication performance. It is found that the proposed beam-shaping approach can still yield power savings on the order of 20% compared to a conventional Gaussian beam under the considered conditions.