Simulation of III-V strained quantum well lasers with coupled concentric racetrack resonators

The simulation of the lasing behavior of semiconductor quantum well structures with accurate description of transport phenomena and optical propagation poses great challenges when complex epitaxial layers are coupled with optical cavities in the transverse direction that are more complex than the well know Fabry-Pérot and distributed feedbackreflector based resonators. In this work, we present an approximate approach for the simulation of an electricallypumped III-V strained quantum well laser with coupled concentric racetrack resonators. The electrical, thermal and optical behavior of an epitaxial stack with at least one quantum well is obtained from a physics based simulator for a reduced dimensionality problem, and this solution is coupled with the cold cavity analysis of the resonator using either finite difference time domain simulation or coupled-mode analysis. The effects of gain and charge transport on the active resonator are then taken into account as a perturbation and the approximate solution derived. Comparison with actual devices based on InGaAlAs/InGaAs/InP and InGaSb/AlGaAsSb/GaSb shows reasonable agreement. The concentric racetrack resonator exhibits complex dispersive behavior, with possible applications in sensing, nonlinear phenomena and optical signal processing.