HIGH-EFFICIENCY AND LOW-THRESHOLD INGAAS ALGAAS QUANTUM-WELL LASERS/

High-efficiency and low-threshold InGaAs/AlGaAs quantum-well laser str uctures have been grown by molecular beam epitaxy. Material characteri zation was performed on polyimide-planarized ridge-waveguide lasers. T he measured material gain data are compared to theoretical calculation s that include the valence-band mixing effects. Total injection curren t densities of 84 and 60 A/cm(2) have been measured from 50-mu m-wide laser diodes with cavity lengths of 2850 mu m (from a double-quantum-w ell sample) and 1770 mu m (from a single-well sample), respectively. M oreover, we have also obtained a cw threshold current as low as 2.1 mA from a 1.7-mu m-wide and 140-mu m-long as-cleaved ridge-waveguide dev ice. In addition, the lateral current leakage for the double-quantum-w ell sample is found to be twice that of the single-well one.