An alloy semiconductor system with a tailorable band-tail and its application to high-performance laser operation: II. Experimental study on InGaN MQW laser for optimization of differential gain characteristics tuned by In compositional fluctuation

Differential gain and carrier lifetime have, been deduced experimentally fo r InGaN MQWs having different magnitudes of In compositional fluctuation an d defect density in the active layer. It has been found that the compositio nal fluctuation and differential gain show a strong correlation in full acc ordance with the theoretical model for a band-tail modified by In compositi onal fluctuation as described in the companion paper (part I). Several lase r characteristics, threshold current density, differential gain and respons e time, were found to be affected by the compositional fluctuation and defe ct density. The optimization of these growth parameters for producing high- performance blue-violet InGaN MQW LDs is also discussed.