Thermally dependent characteristics and spectral hole burning of the double-lasing, edge-emitting quantum-dot laser

Abstract

Thermally induced behavior of double-lasing edge-emitting quantum dot (QD) laser is investigated by coupling the electron/hole rate equation model with thermal analysis. The increase in substrate temperature due to laser self-heating causes the gradual and continual degradation of ground-state slope efficiency, roll-over, which eventually leads to a complete loss of ground-state light emission. Early excited-state spectral hole burning is observed, which is attributed to carrier leakage from the excited-state to the ground-state induced by the vigorous ground-state stimulated emission. At elevated temperatures, the enhanced carrier transport/communication yields the electron/hole occupation probabilities approaching quasithermal equilibrium, i.e., thermal equilibration. Spectral analysis also shows that self-heating results in recovery of the ground-state spectral hole burning of electron, which can be explained by the thermal equilibration. Homogeneous broadening optically synchronizes all the inhomogeneously broadened QDs by involving all the carriers at the same mode in different QDs, so that QD laser’s performance becomes more thermally sensitive. The strong coupling between thermally-induced emission and the spectral hole burning is demonstrated.

Influence of inhomogeneous broadening and deliberately introduced disorder on the width of the lasing spectrum of a quantum dot laser

“…Note that the main results of thorough analyses [8][9][10][11] qualitatively coincide with our results. Proceeding from the analytical dependences obtained, we investigated the dependences of the LS width on the lasing power, the laser cavity loss, the number of QD layers in the active region, and the position of the LS peak.…”

“…Let us consider a laser containing several identical layers of QDs, whose energy distribution is described by the Gaussian law: (10) Here, σ is the rms spread of QDs over energy. Within the generally accepted model, the escape rate depends exponentially on the QD energy: g e (z)/g e0 = exp( ) [14].…”

“…This prob lem was considered previously by numerical methods in terms of rate equations [8][9][10][11]. Both the indepen dent capture of electrons and holes into a QD [8][9][10] and the exciton capture model [11] were considered. However, due to the complexity of the methods pro posed, only some quantitative results from calculating the QD laser spectrum have been obtained; based on these results, one cannot obtain the main regularities and key parameters.…”

Multiscale Electrothermal Modeling of Nanostructured Devices

“…This condition is called acoustics thick limit. The diffusive thermal conductivity is κ = 1 3 v 2 g Cτ . A numerical example of the heat transport for the aforementioned system is provided later.…”

“…Due to the high Joule's heat, confined structures experience strong selfheating effects, which may compromise their performance and the crystalline quality [1], [2]. As the size of the device becomes comparable with the mean free path of charge and heat carriers, the local equilibrium assumption fails and a model going beyond the diffusive approach becomes necessary [3], [4].…”