Abstract: There is provided a semiconductor device that comprises a layered structure configured by layering a first compound semiconductor layer, an active layer, and a second compound semiconductor layer. The semiconductor device further includes a substrate, a first light reflecting layer arranged on the first surface side of the first compound semiconductor layer, and a second light reflecting layer arranged on the second surface side of the second compound semiconductor layer. Further, the second light reflecting layer has a flat shape, a concave surface portion is formed on a substrate surface, the first light reflecting layer is formed on at least the concave surface portion, the first compound semiconductor layer is formed to extend from the substrate surface onto the concave surface portion, and a cavity is present between the first light reflecting layer and the first compound semiconductor layer.

Abstract: A vertical cavity surface emitting device includes a substrate, a first multilayer film reflecting mirror on the substrate, a first semiconductor layer on the first multilayer film reflecting mirror, a light-emitting layer on the first semiconductor layer, and a second semiconductor layer on the light-emitting layer. The second semiconductor layer includes a low resistance region and a high resistance region on an upper surface. The high resistance region is depressed from the low resistance region toward the light-emitting layer outside the low resistance region and impurities of the second conductivity type are inactivated in the high resistance region such that the high resistance region has an electrical resistance higher than an electrical resistance of the low resistance region. A light-transmitting electrode layer is in contact with the low resistance region and the high resistance region, and a second multilayer film reflecting mirror is on the light-transmitting electrode layer.

Abstract: 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.

Abstract: A VCSEL can include: a substrate that passes light therethrough; a phase matching layer over a top mirror stack; a first metal layer over the phase matching layer; and an end metal region over the first metal layer. The phase matching layer and first metal layer have a cooperative thickness to provide reflectivity of at least a predetermined reflectivity threshold for the emission wavelength. A method of making a VCSEL can include: providing a substrate; forming a first mirror stack above the substrate; forming an active region above the first mirror stack; and forming a reflective end above the active region, the reflective end having a phase matching layer and a first metal layer. The phase matching layer and first metal layer have a combined thickness for the reflective end to have a reflectivity of at least a predetermined reflectivity threshold for an emission wavelength of the VCSEL.

Abstract: A method of manufacturing an optoelectronic device including-light-emitting diodes comprising the forming of three-dimensional semiconductor elements made of a III-V compound, each comprising a lower portion and an upper portion and, for each semiconductor element, the forming of an active area covering the top of the upper portion and the forming of at least one semiconductor area of the III-V compound covering the active area. The upper portions are formed by vapor deposition at a pressure lower than 1.33 mPa.

Abstract: A flow cytometer of a blood analyzer including a transverse-electric (TE) laser diode, a flow cell, a quarter wave plate (QWP), a plurality of lenses, and a side scatter detector. The TE laser diode is configured to output a laser beam along an optical axis and has a fast axis full width at half maximum (FWHM) divergence of from about 16 degrees to about 25 degrees. The QWP is disposed along the optical axis between the TE laser diode and the flow cell and configured to circularly polarize the laser beam. The plurality of lenses is disposed between the TE laser diode and the flow cell and configured to focus the laser beam at the flow cell.

Abstract: A visible-light communication and illumination array includes a substrate and plural surface-emitting superluminescent diodes, SLDs, distributed across the substrate. A first set of SLDs of the plural SLDs generates a first light beam having substantially a first wavelength, a second set of SLDs of the plural SLDs generates a second light beam having substantially a second wavelength, and a third set of SLDs of the plural SLDs generates a third light beam having substantially a third wavelength. The array further includes a controller configured to encode at least one of the first light beam, the second light beam and the third light beam to transmit information. A combination of the first light beam, the second light beam and the third light beam produces white light.

Abstract: An illustrative system includes first and second electrical circuits, a free space optics interface assembly, and a feedthrough assembly. The free space optics interface assembly may include an optical transmitter having an input that is electrically coupled to the first electrical circuit, and an optical receiver having an output that is electrically coupled to the second electrical circuit. The feedthrough assembly electrically connects the input of the optical transmitter to the first electrical circuit and includes a first conductive receptacle electrically coupled to a first input pin of the optical transmitter, a second conductive receptacle electrically coupled to a second input pin of the optical transmitter, a first conductive pad providing electrical connection of the first input pin of the optical transmitter to the first electrical circuit, and a second conductive pad providing electrical connection of the second input pin of the optical transmitter to the first electrical circuit.

Abstract: A laser with a hexagonal semiconductor microdisk to solve the problems of a low quality factor of a hexagonal whispering-gallery mode and light exiting difficulty of a triangular whispering-gallery mode is disclosed. Based on physical characteristics of stimulated radiation of gain materials with a high refractive index, the apparatus uses a distributed Bragg reflection layer to reduce an optical loss of a microcavity laser, and uses a hexagonal semiconductor microdisk as an optical resonator and laser gain material. As an optical pump source, the laser provides an optical gain, and when the gain exceeds a microcavity laser threshold, generates laser light for exiting. By controlling a laser spot of the pump source to be located at a corner of the hexagonal microdisk, the laser light in a double-triangular whispering-gallery optical resonance mode is generated after stimulated radiation for exiting.

Abstract: A vertical cavity surface emitter device (e.g., VCSEL or RC-LED) containing a buried index-guiding current confinement aperture layer which is grown, and lithographically processed to define position, shape and dimension of an inner aperture. In a regrowth process, the aperture is filled with a single crystalline material from the third contact layer. The aperture provides for both current and optical confinement, while allowing for higher optical power output and improved thermal conductivity.

Abstract: An embodiment relates to a surface emitting laser device and a light emitting device including the same. The surface emitting laser device according to the embodiment may include a first reflective layer; an active layer disposed on the first reflective layer; an active region disposed on the active layer and having an aperture and an insulation region disposed around the aperture; and a second reflective layer disposed on the active region. The second reflective layer may include a core reflective layer disposed in a position vertically corresponding to the aperture. The embodiment may include a cladding insulation layer disposed around the core reflective layer. The horizontal cross-section of the aperture may be different from the horizontal cross-section of the core reflective layer.

Abstract: A light-emitting diode includes a semiconductor light-emitting stack and a distributed Bragg reflector (DBR) structure. The semiconductor light-emitting stack has a first surface and a second surface opposite to each other. The DBR structure is disposed on one of the first surface and the second surface of the semiconductor light-emitting stack, and includes at least one set of first light-transmitting layers and at least one set of second light-transmitting layers stacked on each other in the first direction. The first light-transmitting layers has interface roughness greater than that of the second light-transmitting layers.

Abstract: Processes for continuous compositional grading for realization of low charge carrier barriers in electro-optical heterostructure semiconductor devices are provided. An example process includes forming, onto one or more semiconductor layers of an electro-optical semiconductor device, a first semiconductor layer associated with a first bandgap value and forming, onto the first semiconductor layer, a grading layer associated with a continuous compositional grading. The example method further includes forming, onto the grading layer, a second semiconductor layer associated with a second bandgap value. The second bandgap value is different than the first bandgap value.

Abstract: A light emitting element includes a stacked structure including, in a stacked state, a first light reflection layer 41 in which a plurality of thin films is stacked, a light emitting structure 20, and a second light reflection layer 42 in which a plurality of thin films is stacked. The light emitting structure includes a first compound semiconductor layer 21, an active layer 23 and, a second compound semiconductor layer 22 which are stacked. The light emitting structure 20 is formed with a light absorbing material layer 71 (32) in parallel to a virtual plane occupied by the active layer 23.

Abstract: The present disclosure relates to a patterned substrate, an epitaxial wafer, a manufacturing method, a storage medium and an LED chip. The patterned substrate is applied to a Micro LED, a substrate body of the patterned substrate is provided with at least one receiving groove capable of receiving at least part epitaxial material dropped during an epitaxial process. At least part excess epitaxial material produced during a high-speed rotational molding process of an epitaxial layer in an MOCVD furnace may drop into the receiving groove and not remain on the epitaxial layer.

Abstract: A semiconductor laser element that includes a semiconductor layer including a waveguide formed in an intra-layer direction of the semiconductor layer and a window region formed in a front-side end face of the waveguide, has a current-laser optical output characteristic in which, at an operating temperature of 25° C.±3° C., a laser optical output has a maximum value at a first driving current value and the laser optical output is at most 20% of the maximum value at a second driving current value greater than the first driving current value, and is not damaged at the second driving current value.

Abstract: A reflector includes a low refractive index layer having a first average refractive index; and a high refractive index layer having a second average refractive index. The low refractive index layer includes a laminate of alternate Ga-doped AlN layers and layers consisting essentially of GaN. The high refractive index layer includes an InGaN layer. The second average refractive index is higher than the first average refractive index.

Abstract: A light emitting device is provided including a switching element. The light emitting device includes a light emitting unit having a plurality of nanostructures that can emit lights with injection of currents, and a transistor provided in correspondence with the light emitting unit and controlling amounts of the currents injected in the nanostructures.

Abstract: An optical device is provided, including a body formed to have a concavity within which an eye box region is defined; and a plurality of addressable vertical cavity surface emitting laser (VCSEL) arrays arranged in the body of the optical device. The one or more VCSEL arrays comprise a plurality of VCSEL subarrays including independently addressable first and second VCSEL subarrays, which are controlled so as to power the first VCSEL subarray and not the second VCSEL subarray to illuminate only a first subregion of the eye box region, or to power the second VCSEL subarray and not the first VCSEL subarray to only illuminate a second subregion of the eye box region.

Abstract: An embodiment relates to a surface emitting laser device and a light emitting device including the same. A surface emitting laser device according to the embodiment may include a first reflective layer; an active layer disposed on the first reflective layer; an aperture area disposed on the active layer and including an aperture and an insulating region; and a second reflective layer disposed in the aperture area. The active layer may comprise a plurality of quantum wells, quantum barriers, and intermediate layers disposed between the quantum wells and the quantum barriers. The quantum wells and the quantum barriers may include a ternary material, and the intermediate layers may comprise a binary material.

Abstract: 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).

Abstract: A semiconductor laser diode is specified, the semiconductor laser diode includes a semiconductor layer sequence having an active layer having a main extension plane and which, in operation, is configured to generate light in an active region and emit light via a light-outcoupling surface, the active region extending from a back surface opposite the light-outcoupling surface to the light-outcoupling surface along a longitudinal direction in the main extension plane, the semiconductor layer sequence having a surface region on which a first cladding layer is applied in direct contact, the first cladding layer having a transparent material from a material system different from the semiconductor layer sequence, and the first cladding layer being structured and having a first structure.

Abstract: The disclosure develops a multi-scale model that partitions the device into different spatial regions where the high carrier domains are treated as reservoirs in local equilibrium and serve as injectors and receptors of carriers into the neighboring reservoirs through tunneling and thermionic emission. The nonequilibrium Green's function (NEGF) formalism is used to compute the dynamics (states) and the kinetics (filling of states) in the entire extended complex device. The local density of states in the whole device is computed quantum mechanically within a multi-band tight binding Hamiltonian. The model results agree with experimental I-V curves quantitatively.

Abstract: 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.

Abstract: VCSELs have a substrate, first and second electrical contacts (ECs), and an optical resonator (OR), having first and second distributed Bragg reflectors (DBRs) and an active layer between the DBRs. The first DBR is between the substrate and the active layer. One of the DBRs has: first and second parts, having different conductivity types, and each with a pair of layers with different refractive indices. A tunnel junction (TJ) is between the parts. The ECs are for electrically pumping the OR such that the TJ is reversely biased during operation of the VCSEL. Either the first DBR includes the parts, having a relative thickness of the second part to a total thickness of the first and second parts between 0.1-0.8, or the second DBR has the parts, the second part being on the TJ facing away from the active layer, and the relative thickness being between 0.15-0.6.

Abstract: Systems and methods disclosed herein include an illumination module for 3D sensing applications. The illumination module may include an array of vertical cavity surface emitting lasers (VCSELs) emitting light, a driver configured to provide current to the array of VCSELs, and an optical element configured to receive the light emitted by the array of VCSELs and output a light pattern from the illumination module.

Abstract: An optical semiconductor device outputting a predetermined wavelength of laser light includes a quantum well active layer positioned between a p-type cladding layer and an n-type cladding layer in thickness direction. The optical semiconductor device includes a separate confinement heterostructure layer positioned between the quantum well active layer and the n-type cladding layer. The optical semiconductor device further includes an electric-field-distribution-control layer positioned between the separate confinement heterostructure layer and the n-type cladding layer and configured by at least two semiconductor layers having band gap energy greater than band gap energy of a barrier layer constituting the quantum well active layer. The optical semiconductor device is applied to a ridge-stripe type laser.

Abstract: In one embodiment, the invention relates to a semiconductor laser comprising a semiconductor layer sequence for generating laser radiation. According to the invention, the semiconductor layer sequence has a geometric structuring on a top side. A resonator is located in the semiconductor layer sequence and is delimited by opposing facets, wherein the facets contain optically active resonator end faces. The structuring ends spaced apart from the facets. The resonator end faces are spaced apart from material removals from the semiconductor layer sequence.

Abstract: A method for fabricating an array of emitters may include providing a first metallization layer for a first set of emitters of a first channel, wherein the first metallization layer comprises a first interchannel portion positioned between the first set of emitters and a second set of emitters of a second channel. The method may include depositing a dielectric layer on the first interchannel portion of the first metallization layer. The method may include providing a second metallization layer for the second set of emitters, wherein the second metallization layer comprises a second interchannel portion positioned between the first set of emitters and the second set of emitters, and wherein the second interchannel portion of the second metallization layer at least partially overlaps the first interchannel portion of the first metallization layer.

Abstract: Disclosed are systems and methods utilizing an infrared probe and discriminating software to rapidly discriminate abnormal tissue processes from normal tissue during surgery, physical examination of in-situ lesions, and in the assessment of biopsy and resected tissue specimens. Examples demonstrate discrimination of cancerous from noncancerous tissues. The discriminating software, i.e. the metrics, algorithms, calibrant spectra, and decision equations, allows tissue to be identified as abnormal or normal using a minimum of infrared (IR) wavelengths in order to be measured rapidly. The probe records IR metrics approximately 1000 times faster than current commercial instruments, i.e. on a timescale fast enough for clinical use. The probe uses a tunable mid-infrared laser with a small set of selected wavelengths that are optimized for detecting the chemical and molecular signatures of tissue specific lesions to include, but not limited to, cancer, preneoplasia, intracellular accumulations (e.g.

Abstract: The embodiment relates to a surface emitting laser device and a light emitting device including the same. The surface-emitting laser device according to the embodiment includes a first reflective layer, an active region disposed on the first reflective layer, a plurality of aperture regions disposed on the active region, including an aperture and an insulating region, a second reflective layer disposed on the aperture region, and a first electrode and a second electrode electrically connected to the first reflective layer and the second reflective layer, respectively. In the aperture region, an outer periphery of the insulating region may have a circular shape, and an outer periphery of the aperture may have a polygonal shape.

Abstract: Surface-emitting semiconductor laser chip (1) comprising a carrier (20), a layer stack (10) arranged on the carrier (20) and having a layer plane (L) extending perpendicularly to the stacking direction (R), a front side contact (310) and a rear side contact (320), in which in operation a predetermined distribution of a current density (I) is achieved by means of current constriction in the layer stack (10), wherein in the carrier (20) an electrical through-connection (200) is provided, which extends from a bottom surface (20a) of the carrier (20) facing away from the layer stack (10) to a surface of the carrier (20) facing the layer stack (10), and the distribution of the current density (I) is significantly influenced by the shape and size of the cross-section of the through-connection (200) parallel to the layer plane (L) on the surface facing the layer stack.

Abstract: A semiconductor laser device is provided with a semiconductor layer including an active layer and a plurality of cladding layers sandwiching the active layer. The active layer includes a stripe-shaped active region, a pair of first refractive index regions and a pair of second refractive index regions sandwiching the active layer and the pair of first refractive index regions. When ? is the laser oscillation wavelength, na is the effective refractive index of the active region, nc is the effective refractive index of the first refractive index regions, nt is the effective refractive index of the second refractive index regions, w is the width of the active region, and m is a positive integer, the semiconductor laser device satisfies na>nt>nc, and the conditions of equations (5), (8) and (9).

Abstract: A surface-emitting laser device according to an embodiment comprises: a first electrode; a substrate arranged on the first electrode; a first reflection layer arranged on the substrate; an active region arranged on the first reflection layer and including a cavity; an opening region arranged on the active region and including an aperture and an insulation region; a second reflection layer arranged on the opening region; a second electrode arranged on the second reflection layer; and a delta doping layer arranged in the opening region. The thickness of the insulation region becomes thinner in the direction of the aperture, and the delta doping layer can be arranged at the aperture.

Abstract: A method for fabricating a semiconductor device includes: providing a substrate having a front surface and a rear surface opposite to the front surface; forming a trench in the front surface of the substrate; forming a gate dielectric layer over the trench; forming a gate electrode that fills a bottom portion of the trench over the gate dielectric layer; forming a sealing layer that includes a first portion covering the gate electrode, the gate dielectric layer, and the front surface of the substrate, and a second portion covering the rear surface of the substrate; selectively removing the second portion of the sealing layer; and performing an annealing process to form a hydrogen treated surface on an interface between the trench and the gate dielectric layer.

Abstract: The present embodiment relates to a light emission device capable of removing zero-order light from output light of an S-iPM laser. The light emission device comprises an active layer and a phase modulation layer. The phase modulation layer includes a base layer and a plurality of modified refractive index regions. In a state in which a virtual square lattice is set on the phase modulation layer, a center of gravity of each modified refractive index region is separated from a corresponding lattice point, and a rotation angle around each lattice point that decides a position of the center of gravity of each modified refractive index region is set according to a phase distribution for forming an optical image. A lattice spacing and an emission wavelength satisfy a condition of M-point oscillation in a reciprocal lattice space of the phase modulation layer.

Abstract: A semiconductor light-emitting device includes a substrate having a first energy bandgap, a first semiconductor layers on the substrate, an active layer on the first semiconductor layer, and a second semiconductor layer on the active layer. The active layer includes a quantum well layer, and a first barrier layer between the first semiconductor layer and the quantum well layer. The first semiconductor layer has a second energy bandgap wider than the first energy bandgap. The quantum well layer has a third energy bandgap narrower than the first and second energy bandgaps. The second semiconductor layer has a fourth energy bandgap wider than the third energy bandgap. The substrate has a refractive index greater than a refractive index of the first semiconductor layer. The refractive index of the first semiconductor layer is not less than a refractive index of the first barrier layer.

Abstract: Processing methods may be performed to form a filled contact hole in a mirror layer of a semiconductor substrate. The method may include forming a contact hole through a mirror layer of the semiconductor substrate by an etch process. The method may include filling the contact hole with a fill material. A portion of the fill material may overlie the mirror layer. The method may also include removing a portion of the fill material external to the contact hole by chemical mechanical polishing landing on the mirror layer.

Abstract: A semiconductor phosphor configured to exhibit photoluminescence upon irradiation with excitation light, including: at least one active layer made of a compound semiconductor and containing an n-type or p-type dopant; and at least two barrier layers made of a compound semiconductor and having a larger band gap than the active layer. The active layer and the barrier layers are alternately stacked. This provides a semiconductor phosphor which allows easy wavelength adjustment, high efficiency and stability.

Abstract: A core and a slab layer that are formed on a lower clad layer are provided. The lower clad layer is formed on a substrate. The core is comprised of a semiconductor and has a rectangular shape in a cross-sectional view. The slab layer is comprised of a semiconductor. The core and the slab layer have a thickness that allows only up to a secondary mode of light to be present. Further, the core and the slab layer are laminated on the lower clad layer. Further, the core and the slab layer are disposed to be optically coupled to each other.

Abstract: A flow cytometer of a blood analyzer including a transverse-electric (TE) laser diode, a flow cell, a quarter wave plate (QWP), a plurality of lenses, and a side scatter detector. The TE laser diode is configured to output a laser beam along an optical axis and has a fast axis full width at half maximum (FWHM) divergence of from about 16 degrees to about 25 degrees. The QWP is disposed along the optical axis between the TE laser diode and the flow cell and configured to circularly polarize the laser beam. The plurality of lenses is disposed between the TE laser diode and the flow cell and configured to focus the laser beam at the flow cell.

Abstract: A surface-emitting semiconductor light-emitting device includes a first semiconductor layers, an active layer on the first semiconductor layer, a photonic crystal layer on the active layer and a second semiconductor layer on the photonic crystal layer. The photonic crystal layer include first protrusions in a first region and second protrusions in a second region. A spacing of adjacent first protrusions is greater than a spacing of adjacent second protrusions. The second semiconductor layer includes a first layer and a second layer on the first layer. The first layer covers first and second protrusions so that a first space remains between the adjacent first protrusions. The first layer includes a first portion provided between the adjacent second protrusions. The second layer includes a second portion provided between the adjacent first protrusions. The first space between the adjacent first protrusions is filled with the second portion of the second layer.

Abstract: To provide a semiconductor device, a semiconductor laser, and a method of producing a semiconductor device that are capable of sufficiently ensuring electrical connection between a transparent conductive layer and a semiconductor layer. [Solving Means] A semiconductor device according to the present technology includes: a first semiconductor layer; a second semiconductor layer; an active layer; and a transparent conductive layer. The first semiconductor layer has a first conductivity type, a stripe-shaped ridge being formed on a surface of the first semiconductor layer. A second width is not less than 0.99 and not more than 1.0 times a first width, a third width is not less than 0.96 and not more than 1.

Abstract: A semiconductor layer stack, a component made therefrom, a component module, and a production method is provided. The semiconductor layer stack has at least two layers (A, B), which, as individual layers, each have an energy position of the Fermi level in the semiconductor band gap, E F - E V < E G 2 applying to the layer (A) and E L - E F < E G 2 applying to the layer (B), with EF the energy position of the Fermi level, EV the energy position of the valence band, EL the energy position of a conduction band and EL?EV the energy difference of the semiconductor band gap EG, the thickness of the layers (A, B) being selected in such a way that a continuous space charge zone region over the layers (A, B) results.

Abstract: Provided is a semiconductor laser diode, including a GaAs/In P substrate and a multi-layer structure on the GaAs/InP substrate. The multi-layer structure includes a lower epitaxial region, an active region and an upper epitaxial region. The active region comprises a first active layer, an epitaxial region and a second active layer, the epitaxial region is disposed between the first active layer and the second active layer, the first active layer comprises one or more quantum well structures or one or more quantum dot structures, and the second active layer comprises one or more quantum well structures or one or more quantum dot structures.

Abstract: A light emitting element includes: a semiconductor structure including: a substrate, an n-side nitride semiconductor layer located on the substrate, and a p-side nitride semiconductor layer located on the n-side nitride semiconductor layer, wherein a p-side nitride semiconductor side of the semiconductor structure is a light extraction face side, and an n-side nitride semiconductor side of the semiconductor structure is a mounting face side; a first protective layer located on and in direct contact with an upper face of the p-side nitride semiconductor layer in a region corresponding to the peripheral portion of the p-side nitride semiconductor layer; and a current diffusion layer located on and in direct contact with an upper face of the p-side nitride semiconductor layer in a region corresponding to the area inside of the peripheral portion. The current diffusion layer does not overlap the first protective layer in a top view.

Abstract: A vertical-cavity surface-emitting laser (VCSEL) array may include an n-type substrate layer and an n-type metal on a bottom surface of the n-type substrate layer. The n-type metal may form a common anode for a group of VCSEL. The VCSEL array may include a bottom mirror structure on a top surface of the n-type substrate layer. The bottom mirror structure may include one or more bottom mirror sections and a tunnel junction to reverse a carrier type within the bottom mirror structure. The VCSEL array may include an active region on the bottom mirror structure and an oxidation layer to provide optical and electrical confinement. The VCSEL array may include an n-type top mirror on the active region, a top contact layer over the n-type top mirror, and a top metal on the top contact layer. The top metal may form an isolated cathode for the VCSEL array.

Abstract: There is described a terahertz illumination source for terahertz imaging.

Abstract: A semiconductor laser element includes: a first nitride semiconductor layer of a first conductivity-type; a second nitride semiconductor layer of a second conductivity-type; and an active region disposed between the first nitride semiconductor layer and the second nitride semiconductor layer, the active region having a single quantum well structure. The active region comprises a first barrier layer, an intermediate layer, a well layer, and a second barrier layer, in this order in a direction from the first nitride semiconductor layer toward the second nitride semiconductor layer. The thickness of the first barrier layer is 20 nm or less. A lattice constant of the intermediate layer is greater than a lattice constant of each of the first barrier layer and the second barrier layer, and smaller than a lattice constant of the well layer. A thickness of the intermediate layer is greater than a thickness of the well layer.

Abstract: A photoelectric conversion element includes a first reflecting mirror provided on a substrate, a resonator provided on the first reflecting mirror, and a second reflecting mirror provided on the resonator. The first reflecting mirror includes a distributed Bragg reflector (DBR) including a plurality of semiconductor layers. A photoelectric conversion layer is provided in at least one layer of the plurality of semiconductor layers.