Very-low-threshold 2.4-μm GaInAsSb-AlGaAsSb laser diodes operating at room temperature in the continuous-wave regime

A GaInAsSb-AlGaAsSb large optical cavity triple-quantum-well structure was grown by molecular-beam epitaxy. Shallow mesa ridge-waveguide lasers with stripe width of 100 μm were fabricated and tested. An internal losses coefficient as low as 4 cm/sup -1/ and a high internal quantum efficiency of 70% were obtained. In the pulsed regime at room temperature, the extrapolated threshold current densities for infinite cavity length is 78 A/cm
²
. The threshold current density per quantum well is as low as 34 A/cm
²
for a 3-mm-long cavity.