A numerical study on base geometry of transistor laser: Quantum-well location effect

We report a numerical method based on both experimental data and physical model to simulate quantum-well dislocation effect inside the base region of a transistor laser of 150μm cavity length. Utilizing a special calculation method, base recombination lifetime is simulated for different quantum-well locations. In order to investigate optical bandwidth dependence on quantum well location coupled carrier photon equations are analyzed. Simulation shows significant enhancement in optical bandwidth (up to ∼51GHz) due to moving the quantum well toward collector while current gain decreases. Also reported in this work is an optimum place for quantum-well to locate in the base region in order to maximize the bandwidth.