AlInGaAs/AlGaAs strained-layer 850 nm vertical-cavitylasers with very low thresholds

Abstract
The authors report a low CW, RT threshold current (Ith) of 156 µA from a 2.8 µm diameter vertical-cavity laser (VCL) with three AlInGaAs quantum wells. Devices show no degradation after 30 h of burn-in testing at a constant current density of 22 kA/cm2 and a junction temperature of 140°C. In addition, devices were measured at various stage temperatures and it was found that the lowest Ith, 110 µA for the 2.8 µm diameter VCL, occurs near 230 K, where the quantum well gain peak and the cavity mode are aligned.