Microscopic simulation of the temperature dependence of static and dynamic 1.3-μm multi-quantum-well laser performance

The temperature dependence of the performance of 1.3-μm Fabry-Perot (FP) multiple-quantum-well (MQW) lasers is analyzed using detailed microscopic simulations. Both static and dynamic properties are extracted and compared to measurements. Devices with different profiles of acceptor doping in the active region are studied. The simulation takes into account microscopic carrier transport, quantum mechanical calculation of the optical and electronic quantum well properties, and the solution of the optical mode. The temperature dependence of the Auger coefficients is found to be important and is represented by an activated form. Excellent agreement between measurement and simulation is achieved as a function of both temperature and doping profile for static and dynamic properties of the lasers, threshold current density, and effective differential gain. The simulations show that the static carrier density, and hence the contribution to the optical gain, varies significantly from the quantum wells on the p-side of the active layer to those on the n-side. Furthermore, the modal differential gain and the carrier density modulation also vary. Both effects are a consequence of the carrier dynamics involved in transport through the MQW active layer. Despite the complexity of the dynamic response of the MQW laser, the resonance frequency is determined by an effective differential gain, which we show can be estimated by a gain-weighted average of the local differential gain in each well.