A surface-emitting semiconductor laser includes a semiconductor laminated structure that includes a first-conductivity-type layer, an active layer, and a second-conductivity-type layer and in which light generated in the active layer is extracted as laser light from a side of the second-conductivity-type layer while resonating along a lamination direction of these layers, a current constriction layer in which the active layer and the second-conductivity-type layer are electrically connected together through an opening, an insulating layer that has translucency with respect to an emission wavelength of the active layer, a first electrode electrically connected to the first-conductivity-type layer, and a second electrode electrically connected to the second-conductivity-type layer, and, in the surface-emitting semiconductor laser, a part of the insulating layer is exposed from the second electrode, and the insulating layer exposed from the second electrode includes a first portion that has a first thickness and a second portion that has a second thickness to make output of light emitted from the active layer smaller than the first portion in comparison with the first thickness and that surrounds the first portion.

A method for making a laser diode with a distributed grating reflector (RT) in a planar section of a semiconductor laser with stabilized wavelength includes providing a diode formed by a substrate (S), a first cladding layer (CL1) arranged on the substrate (S), an active layer (A) arranged on the first cladding layer (CL1) and adapted to emit a radiation, and a second cladding layer (CL2) arranged on the active layer (A), said cladding layers (CL1, CL2) being adapted to form a heterojunction to allow for efficient injection of current into the active layer (A) and optical confinement, and a contact layer. The manufacturing method provides for creating, on a first portion (ZA) of the device, a waveguide (GO) for confinement of the optical radiation and, on the remaining portion (ZP) of the device, two different gratings for light reflection and confinement. The two gratings define two different zones (R1, R2), wherein the first zone (R1) includes a grating of low order and high duty cycle, and is intended for reflection, and the second zone (R2) includes a grating of the same order, or a grating of a higher order than the previous one, and low duty cycle, and is mainly intended for light confinement. The waveguide (GO) for confining the optical radiation is implemented through a lithography and a subsequent etching, whereas the grating (RT) requires a high-resolution lithography and a shallow etching starting from a planar zone.

In one example, a vertical cavity surface emitting laser (VCSEL) may include an active region to produce light at a wavelength, an emission surface to emit the light at the wavelength, a first oxide region spaced apart from the active region by a distance of at least a half-wavelength of the wavelength, a first oxide aperture in the first oxide region, a second oxide region between the first oxide region and the second oxide region, and a second oxide aperture in the second oxide region. The emitted light may have a divergence angle that is based on the respective positions and thicknesses of the first oxide region and the second oxide region.

A surface emitting laser includes a substrate, a plurality of surface emitting laser elements on a first surface of the substrate, a first electrode electrically connected to a first conductive semiconductor of the surface emitting laser elements; and a second electrode electrically connected to a second conductive semiconductor of the surface emitting laser elements. Each of the surface emitting laser elements includes a first reflecting mirror on the substrate; an active layer on the first reflecting mirror; and a second reflecting mirror on the active layer. When a first contact region in which the first electrode and the first conductive semiconductor are connected to each other is on the first surface or in the first conductive semiconductor of the surface emitting laser elements. The first electrode is electrically connected to the light emitting units. The second electrode is electrically connected to each of the light emitting units.

A surface-emitting laser includes a substrate, a lower reflector layer disposed on the substrate, an active layer disposed on the lower reflector layer, and an upper reflector layer disposed on the active layer. The lower reflector layer, the active layer, and the upper reflector layer form a mesa. The mesa has a current confinement structure. The current confinement structure includes a current confinement layer. The current confinement layer includes an oxide layer extending from a periphery of the mesa and an aperture surrounded by the oxide layer. The aperture overlaps the active layer. The aperture has a major axis and a minor axis. A length of the major axis is twice or more a length of the minor axis.

A coupled-cavity vertical-cavity surface-emitting laser (VCSEL) is disclosed. The coupled-cavity VCSEL includes a passive cavity and an additional distributed Bragg Reflector (DBR) not found in conventional VCSELs, all in a monolithic device. By including these two elements, the photon lifetime may be increased by a factor of approximately ten, leading to a reduction in the laser linewidth by a factor of approximately 100 compared to conventional VCSELs. The two additional elements also serve to ensure single-mode operation of the coupled-cavity VCSEL.

A light-emitting device includes a vertical-cavity surface-emitting laser, the resonant cavity of which is transverse multimode supporting transverse modes having rotational symmetry of order two about a main optical axis, and an index-contrast grating including a plurality of pads. The pads include: a central pad, a plurality of peripheral pads, which are periodically arranged along one or more lines that are concentric with respect to the central pad, and which are arranged so that the grating has, with respect to the main optical axis, a rotational symmetry of uneven order higher than or equal to three.

Disclosed herein are self-mixing interferometry (SMI) sensors, such as may include vertical cavity surface emitting laser (VCSEL) diodes and resonance cavity photodetectors (RCPDs). Structures for the VCSEL diodes and RCPDs are disclosed. In some embodiments, a VCSEL diode and an RCPD are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate. In some embodiments, a first and a second VCSEL diode are laterally adjacent and formed from a common set of semiconductor layers epitaxially formed on a common substrate, and an RCPD is formed on the second VCSEL diode. In some embodiments, a VCSEL diode may include two quantum well layers, with a tunnel junction layer between them. In some embodiments, an RCPD may be vertically integrated with a VCSEL diode.

A surface-emitting laser includes a substrate; semiconductor layers provided on the substrate, the semiconductor layers including a lower reflector layer, an active layer, and an upper reflector layer, the semiconductor layers forming a mesa; a first insulating film covering the mesa; and a second insulating film covering the first insulating film, wherein the mesa has a polygonal shape in a direction in which the substrate extends, and a vertex of the mesa in the direction in which the substrate extends has a chamfered portion.

A vertical cavity surface-emitting laser includes a light emitting portion provided on a substrate, a first pad provided on the substrate, the first pad being electrically connected to the light emitting portion, and a second pad provided on the substrate, the second pad being electrically isolated from the light emitting portion and the first pad.