Space Optical Links for Communication Networks

Abstract

Future spacecraft will require a paradigm shift in the way information is transmitted, in light of the continuous increase in the amount of data requiring space links. Current radio-frequency-based communication systems impose a bottleneck on 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. This chapter focuses on communication links where one of the terminals is in space, and it is organized as follows: Section 34.1 gives a quick overview of key concepts of free-spaceoptical communication (FSOC) that aid in understanding how this technology is used to design lasercom links. Section 34.2 describes how the laser communication signals are affected as they propagate through the atmosphere. Sections 34.3 and 34.4 explain the two applications with greater potential, each having unique characteristics and advantages. Finally, Sect. 34.5 provides an insight of what optical satellite networks may progress toward in the future.