4 W quasi-continuous-wave output power from 2 μm AlGaAsSb/InGaAsSb single-quantum-well broadened waveguide laser diodes

AlGaAsSb/InGaAsSb single-quantum-well (SQW) laser diodes emitting at 2 μm were fabricated and tested. At 10–15 °C, the uncoated SQW lasers with 2–3 mm cavity lengths exhibit a threshold current density of $\text{115\hspace{0.17em}}{\mathrm{A/cm}}^{\mathrm{2}},$ a continuous-wave output power of 1.9 W, a differential efficiency of 53%, and a quasi-continuous-wave output power of 4 W. Their performance deteriorates rapidly as output losses increase beyond $\text{10\hspace{0.17em}}{\mathrm{cm}}^{\mathrm{-1}}.$