ABSTRACT
Chapter 4 elaborates on the flight laser transmitters for coherent and direct detection. Chapter 5 discusses the flight optomechanical assembly. The choice of laser transmitter depends on whether the lasercom system uses direct detection or coherent detection. Both types of lasers are available commercially and developed for the fiberoptics communications industry. Versions of such lasers are being developed for use in space or high-altitude platforms such that they can survive launch loads, thermal loads, vacuum, and cosmic radiation of the space environment. Continuous and significant power scaling of laser transmitters is satisfying power requirements for use in space and most uplink power requirements for ground stations. However, wall-plug power efficiency improvements have been fairly limited.
