Spectral Hole Burning and Carrier-Carrier Interaction in Semiconductor Quantum Well Lasers: A Monte Carlo Investigation

Abstract

Carrier trapping in semiconductor quantum wells is a process of fundamental importance for optoelectronic device applications. After several years of both theo¬retical and experimental research a clear picture of this process is not yet available and many contradictory results can be found in the literature. The first quantum approach¹ indicated a quite slow trapping rate and a strong well width dependence, but was followed by several experimental investigations^2–4 which showed a fast trap¬ping rate and no evidence of well width dependence. A more recent and systematic report⁵ was able to partially reconcile theory and experiment indicating at least a weak dependence of the trapping process on well width. Moreover most of the re¬search carried out, both on the experimental and theoretical side, is valid only for low carrier densities while quantum well lasers work at very high density. In this paper we investigate the effect of non-linear phenomena on the carrier capture and related laser function. We show that carrier-carrier (CC) scattering must always be included in the analysis of quantum well lasers because under lasing condition it is responsible for a large fraction of the capture process. Finally we show that, even though the distribution function inside quantum well lasers is always very close to the Fermi shape, a very small difference in the lasing region (spectral hole burning) can have significant effect on the laser performance.