High performance GaAsSb∕GaAs quantum well lasers

Abstract

Ga As Sb ∕ Ga As quantum wells (QWs) with 1.3μm 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 GaAsSb∕GaAs QWs grown with (without) GaAsP strain compensation. High performance EELs and vertical-cavity surface-emitting lasers (VCSELs) are demonstrated using the GaAsSb∕GaAs∕GaAsP strain compensated active region. One EEL achieved an output power up to 0.9W with thresholds as low as 356A∕cm2 under room temperature pulsed operation, while another achieved continuous-wave (cw) operation at temperatures up to 48°C for wavelengths as long as 1260nm. A set of VCSELs achieved room temperature cw operation with output powers from 0.03to0.2mW and lasing wavelengths from 1240to1290nm. 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 20–30nm relative to the cavity mode.