Ultralow‐loss broadened‐waveguide high‐power 2 μm AlGaAsSb/InGaAsSb/GaSb separate‐confinement quantum‐well lasers

Broadening the waveguides of 2 μm AlGaAsSb/InGaAsSb separate‐confinement multiquantum‐well lasers decreases their internal losses to 2 cm−1, while threshold current densities remain as low as 300 A/cm2. The consequently high cw differential efficiency of 0.36 results in output powers of 1.2 W from 100 μm aperture lasers at 15 °C.