ABSTRACT
In semiconductor microstructures of nanometer size, the behavior of electrons is strongly affected by the quantum nature of the electron and exhibits a remarkable dependence on the parameters specifying the structure. Therefore, by appropriate design of the structure parameters, one can implement artificial novel electronic properties unlike the intrinsic characteristics of the bulk materials [1-4]. Recent advanced techniques for crystal growth have enabled precise fabrication of such the quantum structures, and quantum structures have offered very effective and attractive possibilities for improvement in semiconductor laser performances [5, 6]. This chapter presents the fundamental theory of the quantum well (QW) as the most important quantum structure and the optical amplification by stimulated emission in it.
