Gain and Recombination in Quantum Dot Lasers

This paper provides a tutorial review of the physics of recombination and optical gain in quantum dot laser structures using illustrative model computer calculations for an inhomogeneous InAs dot system. Comparisons are made with gain and recombination rate of an InAs quantum well calculated using the same material properties. Attention is drawn to the equivalent role of k-selection in extended state quantum well systems and "location selection" in quantum dot ensembles. Comparisons are also made with representative experimental results for gain, current, and temperature sensitivity of threshold current.