Threshold behavior in quantum-dot nanolasers: effects of inhomogeneous broadening

We investigate the threshold behavior of lasers under various modeling approaches, considering different numbers of nonlasing cavity modes and analyzing the effects of radiation-matter coupling strength, cavity lifetime, and quantum-dot properties. Thermal and electron-electron decoherence are incorporated as phenomenological relaxation processes, in line with established practices. Both spectrally uniform and polydisperse quantum dots are examined. For the former, we observe strong agreement across modeling approaches: the qualitative behavior remains consistent, with threshold pump values showing quantitative shifts depending on the specific model. In the case of polydisperse quantum dots, leading to inhomogeneous broadening, this picture is reaffirmed—each model type exhibits similar qualitative trends, while threshold variations arise due to the stochastic distribution of emitter transition frequencies. Our results confirm that models that assume homogeneous quantum dots are suitable for comparison with experimental data and that inhomogeneous effects can be directly captured using our framework when required.