p-type modulation carbon-doping to InGaAs/AlGaAs quantum wells by MOCVD auto-doping for surface-emitting lasers

We have proposed a novel structure of p-type modulation doped QWs using a carbon auto doping method, and demonstrated carbon auto doping into AlAs layers by LP-MOCVD. We grew p-type modulation doped InGaAs/AlGaAs QWs, and fabricated edge emitting lasers using the QWs and achieved the reduction of the threshold current density for the first time. We estimated threshold current density (160 A/cm/sup 2/ for 1/spl times/10/sup 19/ cm/sup -3/ modulation doped three QWs edge emitting lasers), and showed the threshold reduction compared with undoped and n-type modulation QW VCSELs. The obtained result shows that the p-type modulation doping could improve the laser performance in terms of reduction of turn-on delay time, resulting in the possibility of future parallel optical transmission systems.