Simulation of double quantum well GalnNAs laser diodes

The simulation of double quantum well (QW) GalnNAs ridge-waveguide (RW) lasers is performed over a wide range of cavity lengths and operating temperatures using a comprehensive in-house 2D laser simulator that takes into account all of the major device physics, including current spreading, capture escape processes, drift diffusion in the QW, 2D optical modes and fully resolved lasing spectra. The gain data used by the simulator were fitted to experimental gain spectra measured by the segmented contact method. The gain model includes the band-anticrossing model for the conduction band and a 4 x 4 kldrp model for the valence band. Using a carrier density-dependent and temperature-dependent linewidth broadening parameter, a good fit with experiment over a temperature range of 300-350 K was obtained. A Shockley-Read-Hall (SRH) lifetime of 0.5 ns and an Auger recombination coefficient of 1 x 10^-28 cm⁶/ s, were extracted from the calibration of the laser simulator to experimental device characteristics of broad-area (BA) devices. Using the same set of parameters for BA devices, except for a reduced SRH lifetime of 0.45 ns underneath the etch, 2D simulation results were found to agree well with the measured RW laser operating characteristics. The impact of the various recombination processes in the RW laser at threshold has also been identified using the calibrated laser simulator.