PHOTOPUMPED LASING AT 1.25 MU-M OF GAINNAS-GAAS MULTIPLE-QUANTUM-WELLVERTICAL-CAVITY SURFACE-EMITTING LASERS

We report room-temperature (RT) continuous-wave (CW) photopumped opera tion of long-wavelength vertical-cavity surface-emitting lasers (VCSEL 's) employing a Ga0.7In0.3N0.007As0.933-GaAs multiple-quantum-well (MQ W) active layer grown directly on a GaAs-AlAs distributed Bragg reflec tor (DBR). Evidence for laser oscillation includes spectral linewidth narrowing, clamping of spontaneous emission, and a distinct increase i n slope efficiency at threshold. By taking advantage of lateral growth rate nonuniformity, we obtained laser emission over an extremely broa d 110-nm wavelength range, from 1.146-1.256 mu m. Equivalent threshold current density over this range was estimated at 3.3-10 kA/cm(2).