71% wall-plug efficiency from 780 nm-emitting laser diode with GaAsP quantum well

High-efficiency laser diodes often adopt high mirror loss design to improve the external differential efficiency of the device. However, the significantly elevated threshold carrier density and exacerbated carrier thermal escape restrict the additional advancements in device performance. By replacing the 7 nm InAlGaAs quantum well with an 11 nm GaAsP quantum well, there has been a considerable improvement in the differential gain. Furthermore, the higher conduction band offset has effectively inhibits the carrier thermal escape, which significantly improves the internal differential efficiency and temperature stability of the device. The stripe width of device was 150 μm, and the cavity length was 2 mm. The device was tested under continuous wave current condition with the heat-sink temperature setting to 25 °C. The power conversion effectively is as high as 71% at 5.4 A. The slope efficiency and the threshold current were 1.47 W/A and 0.62 A.