Vertical-cavity surface-emitting lasers with periodic gain and aluminium top contacts

The authors report low threshold current operation of InGaAs/AlGaAs vertical-cavity surface-emitting lasers. A periodic gain structure allows more strained wells to be used than in conventional multiquantum-well devices, offering advantages for high-power devices. Aluminium ohmic contacts grown by molecular beam epitaxy are used on lasers for the first tim