Basic Concepts

Abstract

Chapter 1 summarizes various semiconductor laser phenomena and discusses a simple phenomenologically based approach for modeling a few of the experimental observations. The advantage of simple models is that they provide a feel for some of the most pervasive semiconductor laser characteristics, such as the decrease in lasing threshold with decreasing thickness of the active region. Using such simple models is analogous to viewing a forest from a great distance with low quality binoculars. We are able to recognize the outlines of the forest and distinguish it from the surrounding land, but we can not see clearly enough to tell what kind of trees are in the forest or even if it is tropical or temperate. With the phenomenological model, important parameters such as carrier effective masses, temperature, and band structure must all be implicitly accounted for with phenomenological “constants” that change markedly as soon as the parameters themselves change. Important physics needed for a more general description is that the electrons obey Fermi-Dirac statistics and that as charged particles they interact strongly with themselves and with the lattice. The task of incorporating the relevant physics into the theory is the subject of this and the next four chapters