64/spl deg/C continuous-wave operation of 1.5-/spl mu/m vertical-cavity surface-emitting laser with Al/sub x/O/sub y//GaAs mirror

Until now, the best performance at 1.5 /spl mu/m vertical-cavity surface-emitting lasers (VCSELs) has been reported from double-fused structures consisting of p-AlGaAs/GaAs mirrors, InP based active layers and n-AlAs/GaAs mirrors. For p-mirrors, AlGaAs/GaAs pairs are generally used instead of AlAs/GaAs pairs to reduce free carrier absorption. One way to reduce the free carrier absorption even further is to use low-loss Al/sub x/O/sub y//GaAs DBRs and intra-cavity contacts. The short effective thickness of the Al/sub x/O/sub y//GaAs DBR is also advantageous in reducing the free carrier absorption. In addition, the Al/sub x/O/sub y//GaAs DBR was reported to have high reflectivity and very low scattering loss. We introduced Al/sub x/O/sub y//GaAs DBRs as low loss laser mirrors for long-wavelength VCSELs. Our device consists of an AlAs/GaAs bottom mirror, an Al/sub x/O/sub y//GaAs top mirror and a 2 1/2 /spl lambda/-thick spacer, all grown by MOCVD. 17 strained InGaAs quantum wells are distributed periodically at field intensity maxima between cavity mirrors. The active region consists of 0.7% compressively strained 3.8-nm thick In/sub 0.6/Ga/sub 0.4/As quantum wells and 10-nm-thick lattice-matched InGaAsP barriers having bandgap wavelength of 1.24 /spl mu/m. Photoluminescence is observed at 1527 nm.