Roomhyphen;temperature continuous operation of GaAs/AlGaAs lasers grown on Si by organometallic vaporhyphen;phase epitaxy

摘要

Gradedhyphen;index separatehyphen;confinement heterostructure singlehyphen;quantumhyphen;well GaAs/AlGaAs diode lasers exhibiting continuous (cw) operation at room temperature have been grown on a Si substrate by organometallic vaporhyphen;phase epitaxy, without the use of molecularhyphen;beam epitaxy. To improve the quality of the laser structure, a defecthyphen;filtering layer was incorporated between this structure and a GaAs buffer layer about 1.5 mgr;m thick grown on the substrate. Of four types of defecthyphen;filtering layers investigated, the most effective was one grown with thermal cycling, which made it possible to obtain pulsed threshold current densities as low as 350 A/cm2for broadhyphen;stripe lasers with a cavity length of 500 mgr;m. Ridgehyphen;waveguide lasers with this type of defecthyphen;filtering layer have exhibited cw threshold currents as low as 25 mA and a differential quantum efficiency of 55percnt;.