High performance GaAsSb/GaAs quantum well lasers

GaAsSbGaAs quantum wells (QWs) with 1.3 μm light emission are grown using solid-source molecular beam epitaxy. The growth temperature is optimized based on photoluminescence (PL) linewidth and intensity and edge-emitting laser (EEL) threshold current density; these measurements concur that the optimal growth temperature is ∼490 °C (∼500 °C) for GaAsSbGaAs QWs grown with (without) GaAsP strain compensation. High performance EELs and vertical-cavity surface-emitting lasers (VCSELs) are demonstrated using the GaAsSbGaAsGaAsP strain compensated active region. One EEL achieved an output power up to 0.9 W with thresholds as low as 356 A cm2 under room temperature pulsed operation, while another achieved continuous-wave (cw) operation at temperatures up to 48 °C for wavelengths as long as 1260 nm. A set of VCSELs achieved room temperature cw operation with output powers from 0.03 to 0.2 mW and lasing wavelengths from 1240 to 1290 nm. The temperature characteristics of these devices indicate that the optimal gain-peak cavity-mode tuning for pulsed operation specifies a room temperature PL peak redshift of 20-30 nm relative to the cavity mode.