InGaAlAs/InP MQW Transistor Lasers Based on Step-Ridge Waveguides

We propose and numerically investigate a new step-ridge-waveguide InGaAlAs/InP multi-quantum well (MQW) transistor laser (TL). The carrier nonradiative recombination centers caused by the exposed deep-ridge waveguide sidewall significantly degrade the optoelectronic performance of the TLs. The step-ridge-waveguide structure guides carriers through the center portion of the ridge waveguide, thereby effectively mitigating the effect of the nonradiative recombination defects. Simulation results show that the optoelectronic characteristics of the step-ridge TL are far better than those of the conventional deep-ridge TL, and the current amplification factor of the step-ridge TL is not affected by the laser excitation. This structure provides a new option for the simultaneous enhancement of the optoelectronic performance of TLs.