MOCVD grown InGaAs/GaAs vertical cavity surfaceemittinglaser on GaAs (311)B substrate

Abstract
The authors have realised an InGaAs/GaAs vertical cavity surface emitting laser grown on a GaAs (311)B substrate by metal-organic chemical-vapour deposition. A carbon auto-doping technique was used to avoid the difficulty of p-type doping (>1019 cm–3) AlAs for a distributed Bragg reflector. A low electrical resistance of p-type GaAs/AlAs DBRs on GaAs (311)B was obtained by using delta doping and compositional grading layers. The lowest threshold was 16 mA at room temperature CW operation for a 50 µm diameter device. The threshold current density is 810 A/cm2 which is reasonably low for non-optimised experimental conditions. The polarisation state was stable.