A VCSEL may include an n-type substrate layer and an n-type bottom mirror on a surface of the n-type substrate layer. The VCSEL may include an active region on the n-type bottom mirror and a p-type layer on the active region. The VCSEL may include an oxidation layer over the active region to provide optical and electrical confinement of the VCSEL. The VCSEL may include a tunnel junction over the p-type layer to reverse a carrier type of an n-type top mirror. Either the oxidation layer is on or in the p-type layer and the tunnel junction is on the oxidation layer, or the tunnel junction is on the p-type layer and the oxidation layer is on the tunnel junction. The VCSEL may include the n-type top mirror over the tunnel junction, a top contact layer over the n-type top mirror, and a top metal on the top contact layer.

The present application relates to the technical field of semiconductor optoelectronics, in particular to a multi-active-region cascaded semiconductor laser. The multi-active-region cascaded semiconductor laser comprises: a plurality of cascaded active regions, wherein each cascaded active region comprises a plurality of active regions; and a tunnel junction, arranged on at least one side of the cascaded active region and electrically connected with the cascaded active region; wherein in the cascaded active region, at least one group of adjacent active regions are connected through a barrier layer. In this way, more active regions are added in the periodic gain structure, which improves the internal quantum efficiency of the device and also reduces the carrier density, thereby obtaining more gains. The barrier layer connection does not have the property of introducing a new pn junction, so the layer will not increase the turn-on voltage for device operation, and meanwhile the epitaxial growth is much simpler than that of the tunnel junction.

A method of incorporating a control structure within a VCSEL device cavity using a multiphase growth sequence includes forming a first mirror over a substrate, forming an active region over the first mirror, forming a spacer on a surface of the active region, forming a control structure on a surface of the spacer, and forming a second mirror over the control structure. The active region and the spacer are formed using a molecular beam epitaxy (MBE) process during an MBE phase of the multiphase growth sequence. The second mirror is formed using a metal-organic chemical vapor deposition (MOCVD) process during an MOCVD phase of the multiphase growth sequence. The control structure is formed using a chemical etching process during a transition period between the MBE phase and the MOCVD phase of the multiphase growth sequence.

Several VCSEL devices for long wavelength applications in wavelength range of 1200-1600 nm are described. These devices include an active region between a semiconductor DBR on a GaAs wafer and a dielectric DBR regrown on the active region. The active region includes multi-quantum layers (MQLs) confined between the active n-InP and p-InAlAs layers and a tunnel junction layer above the MQLs. The semiconductor DBR is fused to the bottom of the active region by a wafer bonding process. The design simplifies integrating the reflectors and the active region stack by having only one wafer bonding followed by regrowth of the other layers including the dielectric DBR. An air gap is fabricated either in an n-InP layer of the active region or in an air gap spacer layer on top of the semiconductor DBR. The air gap enhances optical confinement of the VCSEL. The air gap may also contain a grating.

Methods, devices and systems are described for enabling a series-connected, single chip vertical-cavity surface-emitting laser (VCSEL) array. In one aspect, the single chip includes one or more non-conductive regions one the conductive layer to produce a plurality of electrically separate conductive regions. Each electrically separate region may have a plurality of VCSEL elements, including an anode region and a cathode region connected in series. The chip is connected to a sub-mount with a metallization pattern, which connects each electrically separate region on the conductive layer in series. In one aspect, the metallization pattern connects the anode region of a first electrically separate region to the cathode region of a second electrically separate region. The metallization pattern may also comprise cuts that maintain electrical separation between the anode and cathode regions on each conductive layer region, and that align with the etched regions.

A surface emitting laser element array includes multiple two-dimensionally arranged surface-emitting laser element groups each including multiple surface-emitting laser elements. The multiple surface-emitting laser element groups are drivable independently of each other. The multiple surface-emitting laser element groups are arranged in an arrangement region such that the number of surface-emitting laser element groups arranged in a first direction is larger than the number of surface-emitting laser element groups arranged in a second direction perpendicular to the first direction. An irradiation region irradiated with light emitted from the multiple surface-emitting laser element groups has a shape elongated in the first direction. The arrangement region in which the multiple surface-emitting laser element groups are arranged has an aspect ratio closer to 1:1 than the irradiation region.

The invention relates to a semiconductor laser comprising a semiconductor layer arrangement, having an active zone for radiation generation, as well as comprising a first resonator mirror, a second resonator mirror and a resonator arranged between the first and the second resonator mirror, which ends in a direction parallel to a main surface of the semiconductor layer arrangement. The semiconductor laser also comprises a first wavelength-selective absorption element which is arranged between the semiconductor layer arrangement and the first resonator mirror.

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.

A device that includes a metal(III)-polar III-nitride substrate having a first surface opposite a second surface, a tunnel junction formed on one of the first surface or a buffer layer disposed on the first surface, a p-type III-nitride layer formed directly on the tunnel junction, and a number of material layers; a first material layer formed on the p-type III-nitride layer, each subsequent layer disposed on a preceding layer, where one layer from the number of material layers is patterned into a structure, that one layer being a III-nitride layer. Methods for forming the device are also disclosed.

Provided is a vertical cavity surface emitting laser diode (VCSEL) with a small divergence angle. The VCSEL includes a multi-layer structure on a substrate. The multi-layer structure includes an active region and current confinement layers. Each of the current confinement layers has an optical aperture (OA). When the area of the OA of the current confinement layer outside the active region is larger than the areas of the OAs of the current confinement layers inside the active region, such that the VCSEL has a small divergence angle in the short pulse mode.