Semiconductor Lasers and Theory

Abstract

In this chapter, we discuss the oscillation conditions for semiconductor lasers and, then, derive the rate equations, which are the starting point of the study of chaotic dynamics in semiconductor lasers. The semiconductor laser described here is a Fabry-Perot type with a mono-layer of the active region, however other edge-emitting lasers such as multi-quantum well (MQW) lasers and distributed feedback (DFB) lasers can be treated in the same manner as Fabry-Perot lasers. Therefore, the macroscopic features of these lasers show the same behaviors from the viewpoint of chaotic dynamics, although the detailed characteristics strongly depend on the laser structure and the particular values of the device parameters. The relaxation oscillation frequency, which is calculated from the rate equations plays an important role for the dynamics of semiconductor lasers. The Langevin terms, which are stochastic noise effects, are introduced in the rate equations. Some other fundamental characteristics of semiconductor lasers are also discussed.