Abstract: An epitaxial structure includes a substrate, a nucleation layer on the substrate, a buffer layer on the nucleation layer, and a nitride layer on the buffer layer. The nucleation layer consists of regions in a thickness direction, wherein a chemical composition of the regions is Al(1?x)InxN, where 0?x?1. A maximum value of the x value in the regions decreases along the thickness direction, and the x value in the chemical composition of each two regions consists of a fixed region and a gradient region, wherein a gradient slope of the gradient regions is ?0.1%/nm to ?50%/nm, and a stepwise slope of the fixed regions is ?0.1%/loop to ?50%/loop. A thickness of the nucleation layer is less than that of the buffer layer. A surface roughness of the nucleation layer in contact with the buffer layer is greater than that of the buffer layer in contact with the nitride layer.

Abstract: A vertical cavity surface emitting laser (VCSEL) has first and second electrical contacts, and an optical resonator. The optical resonator has first and second distributed Bragg reflectors (DBRs), an active layer, a distributed heterojunction bipolar phototransistor (DHBP), and an optical guide. The DHBP has a collector layer, light sensitive layer; a base layer; and an emitter layer. There is an optical coupling between the active layer and the DHBP for providing an active carrier confinement by the DHBP. The optical guide guides an optical mode within the optical resonator during operation. The optical guide is outside a current flow which can be provided by the first and second electrical contacts during operation of the VCSEL. The optical guide is outside a layer sequence between the first and second electrical contacts in the vertical direction of the VCSEL. The optical guide has an oxide aperture arranged in the second DBR.

Abstract: Surface-emitting laser devices and light-emitting devices including the same are provided. A surface-emitting laser device can include: a first reflective layer and a second reflective layer; and an active region disposed between the first reflective layer and the second reflective layer, wherein the first reflective layer includes a first group first reflective layer and a second group first reflective layer, and the second reflective layer includes a first group second reflective layer and a second group second reflective layer.

Abstract: An optical device has a gallium and nitrogen containing substrate including a surface region and a strain control region, the strain control region being configured to maintain a quantum well region within a predetermined strain state. The device also has a plurality of quantum well regions overlying the strain control region.

Abstract: The present disclosure relates to a light emitting device, a method for preparing the same and a display device. The light emitting device includes a cathode layer, a quantum dot light emitting layer, a hole injection layer and an anode layer which are laminated. The hole injection layer includes a complex metal oxide film comprising two metal oxides that is at least partially oxidated.

Abstract: Embodiments of the present disclosure generally relate to light emitting diodes LEDs and methods of manufacturing the LEDs. The LEDs include a mesa-structure that improves light extraction of the LEDs. Furthermore, the process for forming the LEDs refrains from using physical etching to a quantum well active region of the LEDs to prevent compromising performance at the quantum well sidewall.

Abstract: An optical device has a gallium and nitrogen containing substrate including a surface region and a strain control region, the strain control region being configured to maintain a quantum well region within a predetermined strain state. The device also has a plurality of quantum well regions overlying the strain control region.

Abstract: A polarizer for the display side of a liquid crystal display is provided. The polarizer comprises a polarizing layer, a light collimation layer and a quantum dot diffraction layer. The polarizing layer has a light incident surface and a light exiting surface. The light collimation layer is disposed on the light exiting surface of the polarizing layer. The quantum dot diffraction layer is disposed on the light collimating layer on the opposite side of the polarizing layer, and comprises a diffraction microstructure layer disposed on the light collimation layer, and a quantum dot planarization layer which fills and planarizes the diffraction microstructure layer and can be divided into a plurality of pixel regions.

Abstract: A III-nitride semiconductor light emitting device incorporating n-type III-nitride cladding layers, indium containing III-nitride light emitting region, and p-type III-nitride cladding layers. The light emitting region is sandwiched between n- and p-type III-nitride cladding layers and includes multiple sets of multi-quantum-wells (MQWs). The first MQW set formed on the n-type cladding layer comprises relatively lower indium concentration. The second MQW set comprising relatively moderate indium concentration. The third MQW set adjacent to the p-type cladding layer incorporating relatively highest indium concentration of the three MQW sets and is capable of emitting amber-to-red light. The first two MQW sets are utilized as pre-strain layers. Between the MQW sets, intermediate strain compensation layers (ISCLs) are added. The combination of the first two MQW sets and ISCLs prevent phase separation and enhance indium uptake in the third MQW set.

Abstract: Aspects of the subject disclosure may include, for example, a first distributed Bragg reflector, a second distributed Bragg reflector, an active region with an oxide aperture between the first and second distributed Bragg reflectors, and a dielectric layer, where a positioning of the dielectric layer with respect to the first and second distributed Bragg reflectors and the oxide aperture causes suppression of higher modes of the vertical-cavity surface-emitting laser device. Other embodiments are disclosed.

Abstract: A semiconductor laser device having a diffraction grating is disclosed. The semiconductor laser device comprises a first diffraction grating provided on a substrate, a second diffraction grating continuous to one end of the first diffraction grating along an optical waveguide direction, and an active layer provided above the first diffraction grating. The second diffraction grating has a pitch 1.05 times or greater, or 0.95 times or smaller of the pitch of the first diffraction grating.

Abstract: A semiconductor laser device having a diffraction grating is disclosed. The semiconductor laser device comprises a first diffraction grating provided on a substrate, a second diffraction grating continuous to one end of the first diffraction grating along an optical waveguide direction, and an active layer provided above the first diffraction grating. The second diffraction grating has a pitch 1.05 times or greater, or 0.95 times or smaller of the pitch of the first diffraction grating.

Abstract: An optical device has a gallium and nitrogen containing substrate including a surface region and a strain control region, the strain control region being configured to maintain a quantum well region within a predetermined strain state. The device also has a plurality of quantum well regions overlying the strain control region.

Abstract: A process of forming an epitaxial substrate that includes nitride semiconductor layers is disclosed. The process includes steps of; (a) growing a nucleus forming layer on the substrate, and (b) growing a nitride semiconductor layer on the nucleus forming layer. The step (a) sets first and second growth temperatures in an upstream side and a downstream side, respectively, of the substrate for the flow of the source gases, where the first temperature of the upstream side is at least 5° C. but at most 10° C. lower than the second temperature of the downstream side, and the second temperature is higher than 1100° C.

Abstract: A light-emitting diode includes: an epitaxial-laminated layer having from bottom up: an n-type ohmic contact layer, a first n-type transition layer, an n-type etching-stop layer, a second n-type transition layer, an n-type confinement layer, an active layer, a p-type confinement layer, a p-type transition layer and a p-type window layer; a p electrode on the upper surface of the p-type window layer; a metal bonding layer over the bottom surface of the n-type ohmic contact layer, wherein, the portion corresponding to the p electrode position extends upwards and passes through the n-type ohmic contact layer and the first n-type transition layer, till the n-type etching-stop layer, thereby forming a current distribution adjustment structure such that the injected current would not flow towards the epitaxial-laminated layer right below the p electrode; and a conductive substrate over the bottom surface of the metal bonding layer.

Abstract: In an embodiment, a laser includes a gain section. The gain section includes an active region, an upper separate confinement heterostructure (SCH), and a lower SCH. The upper SCH is above the active region and has a thickness of at least 60 nanometers (nm). The lower SCH is below the active region and has a thickness of at least 60 nm.

Abstract: An illumination apparatus of the disclosure includes a semiconductor light-emitting element and a light conversion element. The semiconductor light-emitting element has a first optical waveguide and a second optical waveguide. The light conversion element has a first light converter and a second light converter. A first emitted light emitted from first optical waveguide enters the first light converter and a second emitted light emitted from the second optical waveguide enters the second light converter. First power applied to the first optical waveguide and second power applied to the second optical waveguide are independent.

Abstract: Aspects of the subject disclosure may include, for example, a first distributed Bragg reflector, a second distributed Bragg reflector, an active region with an oxide aperture between the first and second distributed Bragg reflectors, and a dielectric layer, where a positioning of the dielectric layer with respect to the first and second distributed Bragg reflectors and the oxide aperture causes suppression of higher modes of the vertical-cavity surface-emitting laser device. Other embodiments are disclosed.

Abstract: The invention relates, inter alia, to a method for producing an electro-optical component (10, 200) suitable for emitting electromagnetic radiation (120), wherein in the method a first intermediate layer (60) is applied on a carrier, a second intermediate layer (70) is applied on the first intermediate layer, and after the second intermediate layer has been applied, the buried first intermediate layer is locally modified, wherein as a result of the local modification of the buried first intermediate layer in a lateral direction a refractive index jump is produced which brings about a lateral wave guiding of the electromagnetic radiation (120) in the unmodified region of the first intermediate layer.

Abstract: In order to increase the spectral response range and improve the mobility of the photo-generated carriers (e.g. in an nBn photodetector), a digital alloy absorber may be employed by embedding one (or fraction thereof) to several monolayers of a semiconductor material (insert layers) periodically into a different host semiconductor material of the absorber layer. The semiconductor material of the insert layer and the host semiconductor materials may have lattice constants that are substantially mismatched. For example, this may performed by periodically embedding monolayers of InSb into an InAsSb host as the absorption region to extend the cutoff wavelength of InAsSb photodetectors, such as InAsSb based nBn devices. The described technique allows for simultaneous control of alloy composition and net strain, which are both key parameters for the photodetector operation.

Abstract: A light-emitting device is provided. The light-emitting device comprises a light-emitting stack comprising a first cladding layer of n type, a second cladding layer of p type, and an active layer between the first cladding layer and the second cladding layer wherein the active layer comprises a well layer interposed between adjacent barrier layers. The light-emitting device further comprises a means for reducing a flicker noise of the light-emitting device.

Abstract: The present disclosure involves an apparatus. The apparatus includes a photonic die structure that includes a light-emitting diode (LED) die. The LED die is a vertical LED die in some embodiments. The LED die includes a substrate. A p-doped III-V compound layer and an n-doped III-V compound layer are each disposed over the substrate. A multiple quantum well (MQW) layer is disposed between the p-doped III-V compound layer and the n-doped III-V compound layer. The p-doped III-V compound layer includes a first region having a non-exponential doping concentration characteristic and a second region having an exponential doping concentration characteristic. In some embodiments, the second region is formed using a lower pressure than the first region.

Abstract: A dermatological treatment device includes a device body; a laser diode bar configured to generate laser radiation for delivery to a target area of tissue, the laser diode bar having a fill factor of at least 50%; a power source; and control electronics configured to provide power from the power source to the laser diode bar such that the laser diode bar generates a laser beam; wherein the device is configured for delivering the generated laser beam to the target area of tissue to provide a dermatological treatment.

Abstract: A dermatological treatment device includes a handheld device body, and a laser control circuit housed in the device body and configured to generate laser radiation for delivery to a target area of tissue. The laser control circuit includes a multiple-emitter laser diode and a battery source. The multiple-emitter laser diode includes a monolithic stack of layers formed on a substrate, the monolithic stack of layers including a multiple-emitter region defining at least two emitter junctions, each emitter junction configured to emit a laser beam. The battery source provides current to the laser diode such that each of the at least two emitter junctions concurrently emits a laser beam, the at least two concurrently emitted laser beams forming a collective beam. The device delivers the collective beam to the target area of tissue to provide a dermatological treatment.

Abstract: Tensile strained germanium is provided that can be sufficiently strained to provide a nearly direct band gap material or a direct band gap material. Compressively stressed or tensile stressed stressor materials in contact with germanium regions induce uniaxial or biaxial tensile strain in the germanium regions. Stressor materials may include silicon nitride or silicon germanium. The resulting strained germanium structure can be used to emit or detect photons including, for example, generating photons within a resonant cavity to provide a laser.

Abstract: Implementing a layered hyperbolic metamaterial in a vertical cavity surface emitting laser (VCSEL) to improve thermal conductivity and thermal dissipation thereby stabilizing optical performance. Improvement in the thermal management and power is expected by replacing the distributed Bragg reflector (DBR) mirrors in the VCSEL. The layered metamaterial structure performs the dual function of the DBR and the heat spreader at the same time.

Abstract: A semiconductor buffer structure includes a silicon substrate, a nucleation layer formed on the silicon substrate, and a buffer layer formed on the nucleation layer. The buffer layer includes a first layer formed of a nitride semiconductor material having a uniform composition rate, a second layer formed of the same material as the nucleation layer on the first layer, and a third layer formed of the same material with the same composition ratio as the first layer on the second layer.

Abstract: A semiconductor light emitting device of double hetero junction includes an active layer and clad layers. The clad layers include an n-type layer and p-type layer. The clad layers sandwich the active layer. A band gap energy of the clad layers is larger than that of the active layer. The band gap energy of the n-type clad layer is smaller than of the p-type clad layer.

Abstract: A semiconductor laser device includes an n-type clad layer, a first p-type clad layer and a ridge stripe. The device also includes an active layer interposed between the n-type clad layer and the first p-type clad layer, and a current-blocking layer formed on side surfaces of the ridge stripe. The ridge stripe of the device includes a second p-type clad layer formed into a ridge stripe shape on the opposite surface of the first p-type clad layer from the n-type clad layer. The ridge stripe is formed such that a first ridge width as the width of a surface of the second p-type clad layer exists on the same side as the first p-type clad layer and a second ridge width as the width of a surface of the second p-type clad layer exists on the opposite side from the first p-type clad layer.

Abstract: Tensile strained germanium is provided that can be sufficiently strained to provide a nearly direct band gap material or a direct band gap material. Compressively stressed or tensile stressed stressor materials in contact with germanium regions induce uniaxial or biaxial tensile strain in the germanium regions. Stressor materials may include silicon nitride or silicon germanium. The resulting strained germanium structure can be used to emit or detect photons including, for example, generating photons within a resonant cavity to provide a laser.

Abstract: In order to provide a highly reliable silicon-germanium semiconductor optical element of high luminous efficiency or of low power consumption that can reduce or prevent the occurrence of dislocations or crystal defects on the interface between a light emitting layer or a light absorption layer and a cladding layer, in a silicon-germanium semiconductor optical element, a germanium protective layer 11 of non-light emission is disposed between a germanium light emitting layer or the light absorption layer 10 and a cladding layer 12 disposed above a substrate. The germanium protective layer 11 has the electrical conductivity different from electrical conductivity of the germanium light emitting layer or the light absorption layer 10.

Abstract: In a BH laser which uses InGaAlAs-MQW in an active layer, Al-based semiconductor multi-layer films including an InP buffer layer and an InGaAlAs-MQW layer, and an InGaAsP etching stop layer are formed in a mesa shape, and a p type InP burial layer is buried in side walls of the mesa shape. An air ridge mesa-stripe of a lateral center that is substantially the same as that of the mesa shape is formed on the mesa shape. According to the present structure, a leakage current can be considerably reduced, the light confinement coefficient can be made to be larger than in a BH laser in the related art, and thereby it is possible to implement a semiconductor laser with a low leakage current and a high relaxation oscillation frequency.

Abstract: Semiconductor structures for laser devices are provided. The semiconductor structures have a quantum cascade laser structure comprising an electron injector, an active region, and an electron extractor. The active region comprises an injection barrier, a multiquantum well structure, and an exit barrier. The multiquantum well structure can comprise a first barrier, a first quantum well, a second barrier, a second quantum well, and a third barrier. The energies of the first and second barrier are less than the energy of the third barrier. The energy difference between the energy of the second barrier and the energy of the third barrier can be greater than 150 meV and the ratio of the energy of the third barrier to the energy of the second barrier can be greater than 1.26.

Abstract: Implementing a layered hyperbolic metamaterial in a vertical cavity surface emitting laser (VCSEL) to improve thermal conductivity and thermal dissipation thereby stabilizing optical performance. Improvement in the thermal management and power is expected by replacing the distributed Bragg reflector (DBR) mirrors in the VCSEL. The layered metamaterial structure performs the dual function of the DBR and the heat spreader at the same time.

Abstract: A quantum cascade laser includes a plurality of active layers, each of active layers including a first barrier layer, a first quantum well layer, a second barrier layer, a second quantum well layer, a third barrier layer, a third quantum well layer, and a fourth bather layer provided in this order along a predetermined direction; a plurality of injection layers; and a core layer having the active layers and the injection layers, the active layers and the injection layers being alternately provided along the predetermined direction to form a cascade structure. The first quantum well layer has a film thickness larger than a film thickness of the second quantum well layer. The second quantum well layer has the film thickness larger than a film thickness of the third quantum well layer. In addition, the second barrier layer has a film thickness smaller than a film thickness of the third bather layer.

Abstract: Structures and methodologies to obtain lasing in indirect gap semiconductors such as Ge and Si are provided and involves excitonic transitions in the active layer comprising of at least one indirect gap layer. Excitonic density is increased at a given injection current level by increasing their binding energy by the use of quantum wells, wires, and dots with and without strain. Excitons are formed by holes and electrons in two different layers that are either adjacent or separated by a thin barrier layer, where at least one layer confining electrons and holes is comprised of indirect gap semiconductor such as Si and Ge, resulting in high optical gain and lasing using optical and electrical injection pumping. In other embodiment, structures are described where excitons formed in an active layer confining electrons in the direct gap layer and holes in the indirect gap layer; where layers are adjacent or separated by a thin barrier layer.

Abstract: In a surface-emission laser diode, there is provided, between an active layer and a semiconductor layer that contains Al, Ga and As as major components, a semiconductor layer containing Al, In and P as major components such that the semiconductor layer containing Al, In and P as major components is provided adjacent to the semiconductor layer that contains Al, Ga and As as major components. Further, an interface between the semiconductor layer containing Al, Ga and As as major components and the semiconductor layer containing Al, In and P as major components is coincident to a location of a node of electric field strength distribution.

Abstract: Tensile strained germanium is provided that can be sufficiently strained to provide a nearly direct band gap material or a direct band gap material. Compressively stressed or tensile stressed stressor materials in contact with germanium regions induce uniaxial or biaxial tensile strain in the germanium regions. Stressor materials may include silicon nitride or silicon germanium. The resulting strained germanium structure can be used to emit or detect photons including, for example, generating photons within a resonant cavity to provide a laser.

Abstract: A nitride semiconductor laser includes an electrically conductive support substrate with a primary surface of a gallium nitride based semiconductor, an active layer provided above the primary surface, and a p-type cladding region provided above the primary surface. The primary surface is inclined relative to a reference plane perpendicular to a reference axis extending in a direction of the c-axis of the gallium nitride based semiconductor. The p-type cladding region includes first and second p-type Group III nitride semiconductor layers. The first p-type semiconductor layer comprises an InAlGaN layer including built-in anisotropic strain. The second p-type semiconductor layer comprises semiconductor different from material of the InAlGaN layer. The first nitride semiconductor layer is provided between the second p-type semiconductor layer and the active layer. The second p-type semiconductor layer has a resistivity lower than that of the first p-type semiconductor layer.

Abstract: A semiconductor laser device capable of high output is provided. A semiconductor laser diode includes: a substrate; and a semiconductor stacked structure, which is formed on the substrate through crystal growth. The semiconductor stacked structure includes: an n-type (Alx1Ga(1-x1))0.51In0.49P cladding layer and a p-type (Alx1Ga(1-x1))0.51In0.49P cladding layer; an n-side Alx2Ga(1-x2)As guiding layer and a p-side Alx2Ga(1-x2)As guiding layer, which are sandwiched between the cladding layers; and an active layer, which is sandwiched between the guiding layers. The active layer is formed of a quantum well layer including an AlyGa(1-y)As(1-x3)Px3 layer and a barrier layer including an Alx4Ga(1-x4)As layer that are alternatively repetitively stacked for a plurality of periods.

Abstract: A laser diode and method for fabricating same, wherein the laser diode generally comprises an InGaN compliance layer on a GaN n-type contact layer and an AlGaN/GaN n-type strained super lattice (SLS) on the compliance layer. An n-type GaN separate confinement heterostructure (SCH) is on said n-type SLS and an InGaN multiple quantum well (MQW) active region is on the n-type SCH. A GaN p-type SCH on the MQW active region, an AlGaN/GaN p-type SLS is on the p-type SCH, and a p-type GaN contact layer is on the p-type SLS. The compliance layer has an In percentage that reduces strain between the n-type contact layer and the n-type SLS compared to a laser diode without the compliance layer. Accordingly, the n-type SLS can be grown with an increased Al percentage to increase the index of refraction. This along with other features allows for reduced threshold current and voltage operation.

Abstract: In a surface-emission laser diode, there is provided, between an active layer and a semiconductor layer that contains AI, Ga and As as major components, a semiconductor layer containing AI, In and P as major components such that the semiconductor layer containing AI, In and P as major components is provided adjacent to the semiconductor layer that contains AI, Ga and As as major components. Further, an interface between the semiconductor layer containing AI, Ga and As as major components and the semiconductor layer containing AI, In and P as major components is coincident to a location of a node of electric field strength distribution.

Abstract: A nitride semiconductor laser element has: a nitride semiconductor layer having cavity planes at the ends of a waveguide region, an insulating film formed on an upper face of the nitride semiconductor layer so that the ends on the cavity plane side are isolated from cavity planes, and a first film formed from the cavity plane to the upper face of the nitride semiconductor layer, and covered part of the insulating film surface, the first film has a first region that is in contact with the nitride semiconductor and a second region that is in contact with the insulating film, and is formed from AlxGa1-xN (0<x?1) and a different material from that of the insulating film.

Abstract: A semiconductor laser includes a columnar lamination structure including a first multi-layer reflection mirror, a first spacer layer, an AlxGayIn1-x-yP (where 0?x<1 and 0<y<1) based active layer, a second spacer layer, a second multi-layer reflection mirror, and a lateral mode adjusting layer on a substrate in this order from the substrate and including a current narrowing layer. The current narrowing layer includes an unoxidized region in an in-plane central region and a circular oxidized region in the circumference of the unoxidized region. The later mode adjusting layer includes a high reflection region to correspond to the unoxidized region and a circular low reflection region in the circumference of the high reflection region. On the assumption that a diameter of the unoxidized region is Dox and a diameter of the high reflection region is Dhr, the diameters Dox and Dhr satisfy an expression of 0.8<Dhr/Dox<1.5.

Abstract: A group III nitride substrate has a semi-polar primary surface. A first cladding layer has a first conductivity type, and comprises aluminum-containing group III nitride. The first cladding layer is provided on the substrate. An active layer is provided on the first cladding layer. A second cladding layer has a second conductivity type, and comprises aluminum-containing group III nitride. The second cladding layer is provided on the active layer. An optical guiding layer is provided between the first cladding layer and the active layer and/or between the second cladding layer and the active layer. The optical guiding layer comprises a first layer comprising Inx1Ga1-x1N (0?x1<1) and a second layer comprising Inx2Ga1-x2N (x1<x2<1). The second layer is provided between the first layer and the active layer. The total thickness of the first layer and the second layer is greater than 0.1 ?m. The wavelength of laser light is in a range of 480 nm to 550 nm.

Abstract: A semiconductor laser device includes an n-type clad layer, a first p-type clad layer and a ridge stripe. The device also includes an active layer interposed between the n-type clad layer and the first p-type clad layer, and a current-blocking layer formed on side surfaces of the ridge stripe. The ridge stripe of the device includes a second p-type clad layer formed into a ridge stripe shape on the opposite surface of the first p-type clad layer from the n-type clad layer. The ridge stripe is formed such that a first ridge width as the width of a surface of the second p-type clad layer exists on the same side as the first p-type clad layer and a second ridge width as the width of a surface of the second p-type clad layer exists on the opposite side from the first p-type clad layer.

Abstract: A semiconductor laser device includes a p-type clad layer and an n-type clad layer, a p-side guide layer and an n-side guide layer interposed between the p-type clad layer and the n-type clad layer, and an active layer interposed between the p-side guide layer and the n-side guide layer. The active layer includes at least two quantum well layers and a barrier layer interposed between the quantum well layers adjoining to each other. Each of the p-type clad layer and the n-type clad layer is formed of a (Alx1Ga(1-x1))0.51In0.49P layer (0?x1?1). Each of the p-side guide layer, the n-side guide layer and the barrier layer is formed of a Alx2Ga(1-x2)As layer (0?x2?1). Each of the quantum well layers is formed of a GaAs(1-x3)Px3 layer (0?x3?1). The (Alx1Ga(1-x1))0.51In0.49P layer has a composition satisfying an inequality, x1>0.7. The Alx2Ga(1-x2)As layer has a composition satisfying an inequality, 0.4?x2?0.8.

Abstract: In a BH laser which uses InGaAlAs-MQW in an active layer, Al-based semiconductor multi-layer films including an InP buffer layer and an InGaAlAs-MQW layer, and an InGaAsP etching stop layer are formed in a mesa shape, and a p type InP burial layer is buried in side walls of the mesa shape. An air ridge mesa-stripe of a lateral center that is substantially the same as that of the mesa shape is formed on the mesa shape. According to the present structure, a leakage current can be considerably reduced, the light confinement coefficient can be made to be larger than in a BH laser in the related art, and thereby it is possible to implement a semiconductor laser with a low leakage current and a high relaxation oscillation frequency.

Abstract: Provided is a gallium nitride based semiconductor light-emitting device with a structure capable of enhancing the degree of polarization. A light-emitting diode 11a is provided with a semiconductor region 13, an InGaN layer 15 and an active layer 17. The semiconductor region 13 has a primary surface 13a having semipolar nature, and is made of GaN or AlGaN. The primary surface 13a of the semiconductor region 13 is inclined at an angle ? with respect to a plane Sc perpendicular to a reference axis Cx which extends in a direction of the [0001] axis in the primary surface 13a. The thickness D13 of the semiconductor region 13 is larger than the thickness DInGaN of the InGaN layer 17, and the thickness DInGaN of the InGaN layer 15 is not less than 150 nm. The InGaN layer 15 is provided directly on the primary surface 13a of the semiconductor region 13 and is in contact with the primary surface 13a.

Abstract: An photonic device, comprising one section of a material which is different from the material of another section such that the two sections present different optical birefringent index values. This causes a first set of polarization modes to move in a spectral space with a different velocity than a second set of polarization modes. A bias current, or voltage, is used for controlling the overall birefringence effect in the device. The biasing for controlling the birefringence effect is performed such the TE modes and the TM modes of the device are made to coincide in their respective spectral position. Thus the device is made insensitive, or presents substantially reduced sensitivity, to the polarization of any incoming optical signal.