A COMPARATIVE-STUDY OF TEMPERATURE SENSITIVITY OF INGAASP AND ALGAAS MQW LASERS USING NUMERICAL SIMULATIONS

We used numerical simulation to compare the temperature sensitivity of an InGaAsP MQW laser emitting at 1.55 mu m and an AlGaAs MQW laser at 0.82 mu m. By artificially changing the InGaAsP laser gradually into a structure similar to the AlGaAs laser, we gained quantitative insight into how each material or structural parameter causes the relatively low T-0 of the InGaAsP MQW laser. Using a typical MQW structure we demonstrated the relative importance of parameters involving Auger recombination, current leakage over the quantum barrier, optical confinement and band offset. We found that if these parameters were made the same as the AlGaAs laser, the T-0 of the InGaAsP laser was even better than that of the AlGaAs laser. Our numerical simulation confirmed that the Auger recombination is the main cause of low T-0 in MQW InGaAsP lasers. We also discovered that thermal current leakage over the barrier and Auger recombinations are correlated with each other and both factors must be improved to increase the T-0 of InGaAsP lasers to that of AlGaAs lasers.