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

High-efficiency and low-threshold InGaAs/AlGaAs quantum-well laser structures have been grown by molecular beam epitaxy. Material characterization was performed on polyimide-planarized ridge-waveguide lasers. The measured material gain data are compared to theoretical calculations that include the valence-band mixing effects. Total injection current 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-well sample) and 1770 mu m (from a single-well sample), respectively. Moreover, 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 device. In addition, the lateral current leakage for the double-quantum-well sample is found to be twice that of the single-well one.