Monolithically integrated 940 nm half VCSELs on bulk Ge substrates

High quality n-type AlGaAs distributed Bragg reflectors (DBRs) and lnGaAs multiple quantum wells were successfully monolithically grown on 4-inch off-cut Ge (100) wafers. The grown structures have photoluminescence spectra and reflectance spectra comparable to those grown on conventional bulk GaAs wafers and have smooth morphology and reasonable uniformity. These results strongly support full VCSEL growth and fabrication on larger-area bulk Ge substrates for the mass production of AlGaAs-based VCSELs.