High performance ridge-waveguide AlGaAs/GaAs multiquantum-well lasers grown by molecular beam epitaxy

We describe AlGaAs/GaAs multiquantum-well (MQW) injection lasers with a ridge-waveguide structure wherein an extremely low threshold and a high efficiency are achieved. A ridge-waveguide with a stripe width of 3 µm was formed by Ar⁺ion beam etching to realize a single mode lasing. The threshold current for a 200 µm long laser was 13 mA, and the external differential quantum efficiency as high as 60 % was obtained. Single-mode CW operation with a threshold current of 15 mA, has been successfully achieved at room temperature by the p-side up configuration. The characteristic temperature higher than 200°C was obtained at the heat sink temperature between 10 - 100°C.