Current expansion of high-power diode laser bars

980 nm GaAs/AlGaAs separate confinement hetero-structure single quantum well laser bars were grown by metal organic chemical vapor deposition. The relationships between the etching depth and the bars’ parameters have been studied. When the bar is not etched deep to the active layer, the output power and the slope efficiency are in direct proportion to the etching depth, while the threshold current are in inverse proportion to the etching depth. When the bar is etched deeper than the active layer, the output power and the slope efficiency become lower and the threshold current become higher. The best etching depth is 1.993 mm in the experiment, which is less than the depth of the active layer.