Dephasing effects on laser gain in shallow and deep semiconductor quantum dots

The effects of excitation-induced dephasing were investigated for semiconductor quantum-dot lasers. A quantum kinetic analysis that avoids Markovian approximations was also suggested. A microscopic calculation was performed where epitaxially grown or interface quantum dots with coupling between carriers in the dot states and wetting layer states were considered. The dot gain lineshape broadens due to the addition of dot-well scattering contributions to the dot-dot ones. The different cavity lengths provided a variation in cavity loss and threshold gain for comparison. The experimental data showed that with increasing cavity loss, the threshold current density increases as does the lasing linewidth in agreement with the experimental data.