A surface emitting laser according to one embodiment of the present disclosure includes a mesa part including, in order, a first conductivity-type DBR layer, an active layer, a second conductivity-type DBR layer, and a second conductivity-type contact layer. The surface emitting laser further includes: a first conductivity-type contact layer provided in a region on the first conductivity-type DBR layer side in a positional relationship with respect to the mesa part; a first conductivity-type semiconductor layer that is disposed at a position opposed to the mesa part with the first conductivity-type contact layer interposed therebetween, and is in contact with the first conductivity-type contact layer, the first conductivity-type semiconductor layer having a lower impurity concentration than the first conductivity-type contact layer; a first electrode layer in contact with the first conductivity-type contact layer; and a second electrode layer in contact with the second conductivity-type contact layer.

A vertical cavity surface emitting laser (VCSEL) device may include a substrate layer and a first set of epitaxial layers, for a first VCSEL, disposed on the substrate layer. The first set of epitaxial layers may include a first set of mirrors and at least one first active layer. The VCSEL device may include a second set of epitaxial layers, for a second VCSEL, disposed on the first set of epitaxial layers for the first VCSEL. The second set of epitaxial layers may include a second set of mirrors and at least one second active layer. The first VCSEL and the second VCSEL may be configured to emit light in a light emission direction. The at least one first active layer of the first VCSEL may be offset in the light emission direction from the at least one second active layer of the second VCSEL.

A light-emitting element array includes a substrate, plural light-emitting elements arranged on the substrate, plural constriction grooves being provided in a periphery of each of the plural light-emitting elements and forming a current constriction layer that constricts a current flowing through a light-emitting layer by oxidizing the light-emitting layer, and a block separation portion that is provided in a curved shape so as to include at least one inflection point at which a sign of curvature changes along each of positions where the plural light-emitting elements are arranged, and separates the plural light-emitting elements into plural blocks.

A light-emitting element includes: a laminated structure body 20 which is formed from a GaN-based compound semiconductor and in which a first compound semiconductor layer 21 including a first surface 21a and a second surface 21b that is opposed to the first surface 21a, an active layer 23 that faces the second surface 21b of the first compound semiconductor layer 21, and a second compound semiconductor layer 22 including a first surface 22a that faces the active layer 23 and a second surface 22b that is opposed to the first surface 22a are laminated; a first light reflection layer 41 that is provided on the first surface 21a side of the first compound semiconductor layer 21; and a second light reflection layer 42 that is provided on the second surface 22b side of the second compound semiconductor layer 22. The first light reflection layer 41 includes a concave mirror portion 43, and the second light reflection layer 42 has a flat shape.

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.

A vertical cavity surface-emitting laser configured to emit laser light having a wavelength of 830 nm to 910 nm includes a substrate having a main surface including GaAs, a first distributed Bragg reflector, an active layer, and a second distributed Bragg reflector. The substrate, the first distributed Bragg reflector, the active layer, and the second distributed Bragg reflector are arranged in a first axis direction intersecting the main surface. The main surface has an off angle of 6° or more with respect to a (100) plane. The active layer includes In.sub.xAl.sub.yGa.sub.1-x-yAs (0<x<1, 0≤y<1). The active layer has a strain. An absolute value of the strain is 0.5% to 1.4%.

A light-emitting device according to an embodiment of the present disclosure includes: a semiconductor stack in which a first light reflection layer configured by an arsenic-based semiconductor layer including carbon as an impurity, an active layer, and a second light reflection layer are stacked; a first buffer layer provided on the first light reflection layer side of the semiconductor stack, having one face that faces the semiconductor stack and another face that is on an opposite side of the one face, and configured by a phosphorus-based semiconductor layer; and a second buffer layer provided at least between the first light reflection layer and the first buffer layer, and configured by an arsenic-based semiconductor layer including zinc or magnesium as an impurity.

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.

Self-mixing interferometry (SMI) sensors may include vertical cavity surface emitting lasers (VCSEL), photodetectors, and microelectromechanical systems (MEMS). The VCSEL, photodetectors, and MEMS may be vertically stacked. The MEMS may be moveable with respect to a VCSEL and may change a cavity length associated with the VCSEL. By changing the cavity length associated with the VCSEL, certain properties of emitted light may be changed, such as a wavelength value of the emitted light.