ABSTRACT
Chapters 6 and 7 described semiconductor laser oscillators. Another important function of semiconductor lasers is an optical amplifier. Semiconductor optical amplifiers (SOAs) offer many applications in optical communication systems, including direct amplification of optical signals such as optical power boosting in a transmitter, amplification in a repeater, and preamplification in a receiver, and also applications as a power amplifier to implement a high-power laser source. SOAs can also be used to realize other functions such as optical wavelength conversion, wavelength filtering, and optical phase conjugation. This chapter presents the fundamental characteristics of semiconductor laser amplifiers.
