An embodiment discloses a vertical cavity surface emitting laser including a substrate, a lower reflective layer disposed on the substrate, a laser cavity including an active layer and disposed on the lower reflective layer, an oxide layer disposed on the laser cavity, an upper reflective layer disposed on the oxide layer, a plurality of first holes formed in the upper reflective layer and the oxide layer, and an upper electrode disposed on inner sides of the plurality of first holes and disposed on the upper reflective layer, wherein the oxide layer includes a plurality of light emitting regions spaced apart from each other, and the plurality of first holes are disposed to surround each of the light emitting regions in a plan view.

In some embodiments, the present disclosure relates to a method of making a microlens for a VCSEL device. The method includes forming a first lens layer over a second reflector layer. The first lens layer has a first average concentration of a first element. A first additional reflector layer is formed over the first lens layer. A second lens layer is formed over the first additional reflector layer. The second lens layer has a second average concentration of the first element greater than the first average concentration. A second additional reflector layer is formed over the second lens layer. An oxidation process is performed to oxidize peripheral portions of the first and second lens layers to form oxidized peripheral portions of the first and second lens layer. The oxidized peripheral portions of the second lens layer are wider than the oxidized peripheral portions of the first lens layer.

An optical device may include an emitter array including a plurality of emitter groups. Each emitter group may be independently addressable from other emitter groups, of the plurality of emitter groups, for independently lasing. Emitters of the plurality of emitter groups may be interspersed within the emitter array such that a minimum emitter-to-emitter distance within the emitter array is less than a minimum emitter-to-emitter distance within any of the emitter groups.

A surface emitting laser includes a substrate, a lower contact layer disposed on the substrate, a semiconductor layer mesa including a lower reflector layer, an active layer, an upper reflector layer, and an upper contact layer which are laminated, in the order named, on the lower contact layer, an annular electrode disposed on the upper contact layer, and a light transmitting window situated inside the annular electrode to transmit laser light, wherein the upper reflector layer includes a first region and a second region, the first region being inclusive of an area situated directly below the electrode and the light transmitting window, the second region being inclusive of an area outside the mesa and inclusive of a surrounding area of the first region within the mesa, and wherein a proton concentration in the first region is lower than a proton concentration in the second region.

A Vertical Cavity Surface Emitting Laser (VCSEL) has a mesa having an active region, which has m active layer structures (with m≥2). The active layer structures are electrically connected to each other by a tunnel junction therebetween. The mesa has an optical resonator, which has first and second DBRs. The active region is between the first and second DBRs. The VCSEL has first and second electrical contacts, which provide electrical current to the active region, and an electrical control contact, which controls gain-switched laser emission of the VCSEL by at least 1 up to m−1 active layer structures by a current between the electrical control contact and the first or second electrical contact. A current aperture is between the active region and the first or second electrode. A distance between the current aperture and a furthest active layer structure is at least three times the laser light's wavelength.

An optoelectronic device includes a semiconductor substrate with a first set of epitaxial layers formed on an area of the substrate defining a lower distributed Bragg-reflector (DBR) stack. A second set of epitaxial layers formed over the first set defines a quantum well structure, and a third set of epitaxial layers, formed over the second set, defines an upper DBR stack. At least the third set of epitaxial layers is contained in a mesa having sides that are perpendicular to the epitaxial layers. A dielectric coating extends over the sides of at least a part of the mesa that contains the third set of epitaxial layers. Electrodes are coupled to the epitaxial layers so as to apply an excitation current to the quantum well structure.

A semiconductor laser including: a first mirror layer; a second mirror layer; an active layer, a current confinement layer, a first region, and a second region, in which the first mirror layer, the second mirror layer, the active layer, the current confinement layer, the first region, and the second region constitute a laminated body, the first region and the second region constitute an oxidized region of the laminated body, in a plan view, the laminated body includes a first part, a second part, and a third part disposed between the first part and the second part and resonating light generated in the active layer, and in a plan view, at least at a part of the third part, W1>W3 and W2>W3, W1 is a width of the oxidized region of the first part, W2 is a width of the oxidized region of the second part, and W.sub.3 is a width of the oxidized region of the third part.

A vertical-cavity surface-emitting laser includes a substrate having a main surface, a first lower distributed Bragg reflector that extends to an edge of the main surface, a III-V compound semiconductor layer disposed on the first lower distributed Bragg reflector, a second lower distributed Bragg reflector disposed on the III-V compound semiconductor layer, an active layer disposed above the second lower distributed Bragg reflector and an upper distributed Bragg reflector disposed on the active layer. The first lower distributed Bragg reflector includes a first layer and a second layer that are alternately arranged. The upper distributed Bragg reflector includes a third layer and a fourth layer that are alternately arranged. The III-V compound semiconductor layer is free of aluminum or has an aluminum composition less than an aluminum composition of the third layer. The first layer has an aluminum composition greater than the aluminum composition of the third layer.

A vertical cavity surface emitting laser (VCSEL) device includes a microlens arranged over a reflector stack. The reflector stack includes alternating reflector layers of a first material and a second material. The microlens stack includes a first lens layer, a second lens layer arranged over the first lens layer, and a third lens layer arranged over the second lens layer. The first lens layer includes a first average concentration of a first element and has a first width. The second lens layer includes a second average concentration of the first element greater than the first average concentration and has a second width smaller than the first width. The third lens layer includes a third average concentration of the first element greater than the second average concentration and has a third width smaller than the second width.

A multi-junction VCSEL is formed by as a compact structure that reduces lateral current spreading by reducing the spacing between adjacent active regions in the stack of such regions used to from the multi-junction device. At least two of the active regions within the stack are located adjacent peaks of the intensity profile of the VCSEL, with an intervening tunnel junction positioned at a trough between the two peaks. The alignment of the active regions with the peaks maximizes the generated optical power, while the alignment of the tunnel junction with the trough minimizes optical loss. The close spacing on adjacent peaks forms a compact structure (which may even include a cavity having a sub-λ optical length) that lessens the total path traveled by carriers and therefore reduces lateral current spread.