GaAs:GaAlAs ridge waveguide lasers and their monolithic integrationusing the ion beam etching process

The fabrication and performance characteristics of GaAs/GaAlAs ridge waveguide lasers are discussed. Threshold currents as low as 8 mA and differential quantum efficiencies as high as 90% were obtained for 250-μm-long graded-index separate-confinement heterostructure with single quantum well (GRINSCH SQW) lasers. High-speed short-cavity ridge waveguide lasers for which both the ridge stripe and one-mirror facet were formed by Ar-ion beam etching were achieved. The dependence of threshold current and lasing spectra on the cavity length were theoretically and experimentally investigated. This process was successfully used to integrate a laser diode monolithically with a photodiode or a field-effect transistor