Numerical simulation of the dynamic response of self-assembled In0.4Ga0.6As/GaAs quantum dot lasers

摘要

Self-assembly effects in strained epitaxy have made it possible to grow high quality semiconductor dot structures. Recently several groups have shown good performance in quantum dot lasers. In particular for the In$-0.4$/Ga$- 0.6$/As/GaAs quantum dot lasers differential gain of approximately 10$+$MIN@14$/ cm$+2$/ and modulation bandwidths of 7 - 8 GHz have been demonstrated. In this paper, we examine the electronic, optical and dynamic properties of self-assembled lasers. The formalism is based on an eight-band k.p model and a modified rate equations for quantum dots. A Monte-Carlo simulation is also done to compare with the rate equation results. Our results will focus on the following issues: (1) the role of cavity loss and quantum dot density in determining the position of the lasing peaks (i.e. whether ground state or excited state lasing with occur); (2) the dynamic response of quantum dot lasers and the gain compression factor due to Pauli exclusion principle.