A Vertical Cavity Surface Emitting Laser (VCSEL) capable of providing high output of fundamental transverse mode while preventing oscillation of high-order transverse mode is provided. The VCSEL includes a semiconductor layer including an active layer and a current confinement layer, and a transverse mode adjustment section formed on the semiconductor layer. The current confinement layer has a current injection region and a current confinement region. The transverse mode adjustment section has a high reflectance area and a low reflectance area. The high reflectance area is formed in a region including a first opposed region opposing to a center point of the current injection region. A center point of the high reflectance area is arranged in a region different from the first opposed region. The low reflectance area is formed in a region where the high reflectance area is not formed, in an opposed region opposing to the current injection region.

A method of manufacturing a light emitting element includes, at least: (A) forming a stacked structure 20 which includes a GaN-based compound semiconductor and in which a first compound semiconductor layer 21, an active layer 23, and a second compound semiconductor layer 22 are stacked, and forming a concave mirror section 43 on a first surface side of the first compound semiconductor layer 21; then (B) forming a photosensitive material layer 35 over the second compound semiconductor layer 22; and thereafter (C) exposing the photosensitive material layer 35 to light from the concave mirror section side through the stacked structure 20, to obtain a treatment mask layer including the photosensitive material layer 35, and then processing the second compound semiconductor layer 22 by use of the treatment mask layer.

A surface emitting laser element includes a first reflecting mirror; an active layer over the first reflecting mirror; a second reflecting mirror over the active layer; and a multilayer film over the second reflecting mirror. The multilayer film has a side surface including one film and inclined with respect to a principal surface of the second reflecting mirror. The multilayer film includes, in a thickness direction, two or more pairs of a first film having a first refractive index and a second film having a second refractive index higher than the first refractive index. The multilayer film has a center portion and a peripheral portion around the center portion in plan view in a direction perpendicular to the principal surface. The peripheral portion includes the side surface.

A light emitting element according to the present disclosure includes a first light reflecting layer 41, a laminated structure 20, and a second light reflecting layer 42 laminated to each other. The laminated structure 20 includes a first compound semiconductor layer 21, a light emitting layer 23, and a second compound semiconductor layer 22 laminated to each other from a side of the first light reflecting layer. Light from the laminated structure 20 is emitted to an outside via the first light reflecting layer 41 or the second light reflecting layer 42. The first light reflecting layer 41 has a structure in which at least two types of thin films 41A and 41B are alternately laminated to each other in plural numbers. A film thickness modulating layer 80 is provided between the laminated structure 20 and the first light reflecting layer 41.

A VCSEL can include: an active region configured to emit light; a blocking region over or under the active region, the blocking region defining a plurality of channels therein; a plurality of conductive channel cores in the plurality of channels of the blocking region, wherein the plurality of conductive channel cores and blocking region form an isolation region; a top electrical contact; and a bottom electrical contact electrically coupled with the top electrical contact through the active region and plurality of conductive channel cores. At least one conductive channel core is a light emitter, and others can be spare light emitters, photodiodes, modulators, and combinations thereof. A waveguide can optically couple two or more of the conductive channel cores. In some aspects, the plurality of conductive channel cores are optically coupled to form a common light emitter that emits light (e.g., single mode) from the plurality of conductive channel cores.

A high-contrast grating (HCG) structure and method of fabrication. The grating of the HCG is formed over a structural spacer layer, allowing a wider range of grating patterns, such as post and other forms which are lack structural support when fabricated over an air spacing beneath the grating elements. The technique involves etching the HCG grating, followed by oxidizing through this HCG grating into an oxide spacer layer beneath it creating a low-index area beneath the grating. This form of HCG reflector can be utilizes as upper and/or lower reflectors in fabricating vertical cavity surface emitting lasers (VCSELs).

Provided is a vertical cavity surface emitting laser diode (VCSEL). A tunnel junction with a high doping concentration is provided in the VCSEL. An n-type semiconductor layer of the tunnel junction has stress relative to the substrate, and is doped with at least one element such that the tunnel junction not only has a high doping concentration, but also the epitaxial layer can be oxidized and the oxidation rate is relatively stable during the oxidation process. Alternatively, the n-type semiconductor layer is doped with at least two elements. As a result, the oxidation process of the VCSEL can be stably performed, and the resistance of the tunnel junction with a high doping concentration is low. The tunnel junction is suitable to be arranged between two active layers of the VCSEL or between the p-type semiconductor and the n-type semiconductor layer of the VCSEL.

A widely tunable vertical-cavity surface-emitting laser (VCSEL) having a semiconductor cavity followed by an air-gap over which is a movable reflector. Lasing wavelength is controlled by a combination of the resonance of the semiconductor cavity, which is fixed, and the resonance of the air cavity, which can be changed by moving the reflector. Tuning range and slope of the VCSEL are increased by configuring the semiconductor cavity to be antiresonant at the center of the tuning range, which forces electromagnetic energy to be confined more strongly in the air gap than in the semiconductor, thus making emission wavelength more sensitive to the displacement of the tuning mirror.

A vertical cavity surface emitting laser includes a first laminate including first semiconductor layers having a first Al composition, and second semiconductor layers having a second Al composition greater than the first Al composition; a current confinement structure including a current aperture and a current blocker; a first compound semiconductor layer adjacent to the current confinement structure; and a second compound semiconductor layer adjacent to the first laminate and the first compound semiconductor layer. The first compound semiconductor layer has a first aluminum profile changing monotonously in a direction from the first laminate to the current confinement structure from a first minimum Al composition within a range greater than the first Al composition and smaller than the second Al composition to a first maximum Al composition. The second compound semiconductor layer has an Al composition greater than the first Al composition and smaller than the first maximum Al composition.

A microelectromechanical systems (MEMS)-tunable vertical-cavity surface-emitting laser (VCSEL) in which the MEMS mirror is bonded to the active region. This allows for a separate electrostatic cavity that is outside the laser's optical resonant cavity. Moreover, the use of this cavity configuration allows the MEMS mirror to be tuned by pulling the mirror away from the active region. This reduces the risk of snap down. Moreover, since the MEMS mirror is now bonded to the active region, much wider latitude is available in the technologies that are used to fabricate the MEMS mirror. This is preferably deployed as a swept source in an optical coherence tomography (OCT) system.