Abstract: A VCSEL array comprises a plurality of non-isolated VCSEL emitters. Each non-isolated VCSEL emitter comprises a first reflector region, a current confining oxide layer, an oxide aperture, an active region, and a second reflector region. The current confining oxide layer and oxide aperture are made by oxidizing a relatively high Al-content layer via separate oxidation holes. The separate oxidation holes surround the oxide aperture. The first reflector regions of the plurality of non-isolated VCSEL structures are connected such that they are not isolated from each other completely by any isolation structure, and the second reflector regions of the plurality of non-isolated VCSEL structures are connected such that they are not isolated from each other completely by any isolation structure.

Abstract: A bottom-emitting multijunction VCSEL array includes a first reflector region, a multijunction active region, and a second reflector region. In one aspect, the multijunction VCSEL array is attached to a submount by flip-chip bonding. In another aspect, the multijunction VCSEL array further includes a contact layer formed between the first reflector region and the substrate. The multijunction VCSEL array is attached to a submount by flip-chip bonding.

Abstract: A VCSEL array comprises series-connected VCSEL sub-arrays formed on a single chip. The VCSEL sub-arrays each comprises VCSEL emitters fabricated on a semi-insulating layer. A common cathode contact of a VCSEL sub-array is electrically connected to a common anode contact of a neighboring VCSEL sub-array. To reduce leakage, the bandgap energy level of the semi-insulating layer is higher than the photon energy of the output beam. In one embodiment, the semi-insulating layer is grown on a conductive layer. A common cathode contact of the last VCSEL sub-array in a series is electrically connected to the conductive layer. In another embodiment, multiple wire-bonding areas are electrically connected to common anode contacts of multiple VCSEL sub-arrays respectively. The wire-bonding areas provide different input impedance options for a VCSEL array.