STRAINED ALGAINAS/ALGAAS QUANTUM-WELLS AND QUANTUM-WELL LASERS GROWN BY MOLECULAR-BEAM EPITAXY

Suitable growth conditions for strained AlGaInAs grown on GaAs substrates by molecular beam epitaxy (MBE) are presented and strained layer multiple quantum well AlGaInAs lasers grown by MBE are demonstrated. Low temperature photoluminescence was used to characterize quantum wells grown at different temperatures with different Al, Ga, and In compositions to establish growth parameters. Acceptable growth conditions were found for substrate temperatures between 575-degrees-C and 625-degrees-C. Using these results strained layer quaternary multiple quantum well lasers with nominally (Al0.3Ga0.7)0.7In0.3As active regions were grown. Lasers grown at 575 and 600-degrees-C have emission wavelengths of 790 and 770 nm and threshold current densities on broad area (80 mum x 500 mum) devices of 306 and 326 A/cm2, respectively. The difference in emission wavelength between the samples is caused by an increase in indium desorption from the grwoth surface with increasing substrate temperatures. This is the first presentation of AlGaInAs quantum well lasers grown by MBE.