30°C CW operation of 1.52 µm InGaAsP/AlGaAsvertical cavity laserswith in situ built-in lateral current confinement by localised fusion

1.52 µm double fused InGaAsP/AlGaAs vertical cavity surface emitting lasers with in situ built-in lateral current confinement were fabricated using a localised wafer fusion process. A threshold current of 2.5 mA at 4 V was obtained for devices with a 10 × 10 µm2 current aperture. These devices operate CW up to 30°C. The width of the dominant mode is less than 0.1 nm and the sidemode suppression ratio is 30 dB.