ABSTRACT
This chapter presents the basic theory and characteristics of stimulated emission and optical amplification gain in semiconductors. The former is the most important principle that enables semiconductor lasers to be implemented, and the latter is the most important parameter for analysis of the laser performances. First, stimulated emission in semiconductors is explained, and then quantum theory analysis and statistic analysis using the density matrix of the optical amplification gain are given. Stimulated emission and optical gain in semiconductor quantum well structures will be presented in the next chapter.
