Free-space optical links for space communication networks

TL;DR

This paper discusses the emergence of free-space optical communication as a promising solution to overcome bandwidth limitations in space communication, highlighting recent demonstrations and ongoing projects in the field.

Contribution

It provides an overview of the basic principles, recent advancements, and current trends in space laser communication technology.

Findings

Demonstrated in-orbit fundamental principles of lasercom

Lasercom reduces satellite size, weight, and power requirements

Increasing projects aim to deploy space laser communication systems

Abstract

Future spacecraft will require a paradigm shift in the way the information is transmitted due to the continuous increase in the amount of data requiring space links. Current radiofrequency-based communication systems impose a bottleneck in the volume of data that can be transmitted back to Earth due to technological as well as regulatory reasons. Free-space optical communication has finally emerged as a key technology for solving the increasing bandwidth limitations for space communication while reducing the size, weight and power of satellite communication systems, and taking advantage of a license-free spectrum. In the last few years, many missions have demonstrated in orbit the fundamental principles of this technology proving to be ready for operational deployment, and we are now witnessing the emergence of an increasing number of projects oriented to exploit space laser communication (lasercom) in scientific and commercial applications. This chapter describes the basic principles and current trends of this new technology.