Effect of heterobarrier leakage on the performance of high power 1.5-μm InGaAsP multiple quantum well lasers

Eye-safe semiconductor lasers are in demand for development of laser range finder and countermeasure systems. These applications require high level of pulsed optical power. We carried out a comprehensive study of the nature of power saturation in 1.5-μm high power InGaAsP/InP multiple quantum well two step graded SCH lasers. We calculated the internal efficiency normalized to its threshold value for narrow waveguide devices from both the experimental L-I curves and the simulation results. The modeling explains qualitatively all experimental observations. The quantitative discrepancy can be understood taking into account two factors: device overheating even for short pulse operation at high current densities and the increase of the internal loss with current above threshold