Optimization of high power AlGaInP laser diodes at 626 nm

Abstract

The rapid advancement of $$^{9}\hbox {Be}^{+}$$ 9 Be + ion-based quantum computing is creating a high demand for scalable and specialized laser sources. For this purpose, laser radiation at 313 nm is necessary which is generated by frequency doubling of 626 nm laser emission. Laser sources in this spectral region lack simplicity and need to be miniaturized. We carry out a systematic improvement of room temperature semiconductor laser structures emitting at 626 nm. They are based on a GaInP single quantum well embedded in AlGaInP grown on GaAs. We first investigate the structure theoretically and determine its limits and optima. We select the three most promising quantum well combinations, which are grown by metal-organic vapor-phase epitaxy. Furthermore, we fabricate broad-area lasers with dimensions of 1600 $$\upmu$$ μ m $$\times$$ × 100 $$\upmu$$ μ m. All structures show laser operation around 626 nm. We are able to achieve a threshold current density of 721 A/cm2, a slope of 0.384 mW/mA and total maximum output power of 708 mW under pulsed excitation. Based on these results, we believe that quantum computing focusing on beryllium ions will highly benefit from these results.