Prototype Development and Validation of a Beam-Divergence Control System for Free-Space Laser Communications

TL;DR

This paper presents a prototype system for dynamically controlling laser beam divergence in free-space optical communications, aiming to optimize link performance amid variable conditions.

Contribution

The paper introduces a novel prototype for adaptive beam-divergence control, enabling improved performance in space laser communication systems.

Findings

Prototype successfully demonstrated dynamic divergence control

Validation tests confirmed system performance

Potential for integration into versatile lasercom terminals

Abstract

Being able to dynamically control the transmitted-beam divergence can bring important advantages in free-space optical communications. Specifically, this technique can help to optimize the overall communications performance when the optimum laser-beam divergence is not fixed or known. This is the case in most realistic space laser communication systems, since the optimum beam divergence depends on multiple factors that can vary with time, such as the link distance, or cannot be accurately known, such as the actual pointing accuracy. A dynamic beam-divergence control allows to optimize the link performance for every platform, scenario, and condition. NICT is currently working towards the development of a series of versatile lasercom terminals that can fit a variety of conditions, for which the adaptive element of the transmitted beam divergence is a key element. This manuscript presents a prototype of a beam-divergence control system designed and developed by NICT and Tamron to evaluate this technique and to be later integrated within the lasercom terminals. The basic design of the prototype is introduced as well as the first validation tests that demonstrate its performance.