Microscopic theory of laser gain in semiconductor quantum wells

This article reviews a microscopic theory to compute gain and absorption spectra of semiconductor quantum-well structures. The single-particle energies (band structure) are calculated by using LUttinger-Kohn theory in the envelope function approximation. The Coulomb-interacting electron-hole plasma in the laser gain region is treated at the level of quantum-kinetic equations in the Markov limit. Examples for results are presented for narrow-and wide-gap III-V and II-VI quantum-well systems.