Abstract: A method for manufacturing a GaN-based surface-emitting laser by an MOVPE includes: (a) growing a first cladding layer with a {0001} growth plane; (b) growing a guide layer on the first cladding layer; (c) forming holes in a surface of the guide layer by etching, the holes being two-dimensionally periodically arranged within a plane parallel to the guide layer; (d) etching the guide layer by using an etchant having selectivity to the {0001} plane and a {10?10} plane of the guide layer; (e) supplying a gas containing a nitrogen source to cause mass transport without supplying a group-III material gas, and then supplying the group-III material gas for growth, whereby a first embedding layer closing openings of the holes is formed to form a photonic crystal layer; and (f) growing an active layer and a second cladding layer in this order on the first embedding layer.

Abstract: A method for manufacturing an optical semiconductor device, includes the steps of: forming a plurality of compound semiconductor layers including a sacrificial layer, an absorption layer, and a core layer; forming a first mesa from the plurality of compound semiconductor layers; forming an embedding layer that is a semiconductor layer having the first mesa embedded therein; after the step of forming the embedding layer, etching the sacrificial layer to form a chip including the plurality of compound semiconductor layers and the embedding layer; bonding the chip to a substrate comprising silicon and having a waveguide; and etching a portion of the first mesa of the chip bonded to the substrate to form a second mesa adjacent to the first mesa. The second mesa includes the core layer and is optically coupled to the waveguide of the substrate.

Abstract: The present embodiment relates to a semiconductor light-emitting element or the like including a structure for suppressing deterioration in the quality of an optical image caused by an electrode blocking a part of light outputted from a phase modulation layer. The semiconductor light-emitting element includes a phase modulation layer having a basic layer and a plurality of modified refractive index regions, and the phase modulation layer includes a first region at least partially overlapping the electrode along a lamination direction and a second region other than the first region. Among the plurality of modified refractive index regions, only one or more modified refractive index regions in the second region are disposed so as to contribute to formation of an optical image.

Abstract: A semiconductor light emitting element that can form a useful beam pattern is provided. A semiconductor laser element LD includes an active layer 4, a pair of cladding layers 2 and 7 between which the active layer 4 is interposed, and a phase modulation layer 6 optically coupled to the active layer 4. The phase modulation layer 6 includes a base layer 6A and different refractive index regions 6B that are different in refractive index from the base layer 6A. The different refractive index regions 6B desirably arranged in the phase modulation layer 6 enable emission of laser light including a dark line with no zero-order light.

Abstract: A smart light source configured for visible light communication. The light source includes a controller comprising a modem configured to receive a data signal and generate a driving current and a modulation signal based on the data signal. Additionally, the light source includes a light emitter configured as a pump-light device to receive the driving current for producing a directional electromagnetic radiation with a first peak wavelength in the ultra-violet or blue wavelength regime modulated to carry the data signal using the modulation signal. Further, the light source includes a pathway configured to direct the directional electromagnetic radiation and a wavelength converter optically coupled to the pathway to receive the directional electromagnetic radiation and to output a white-color spectrum. Furthermore, the light source includes a beam shaper configured to direct the white-color spectrum for illuminating a target of interest and transmitting the data signal.

Abstract: In a semiconductor light emitting element provided with an active layer 4, a pair of cladding layers 2, 7 between which the active layer 4 is interposed, and a phase modulation layer 6 optically coupled to the active layer 4, the phase modulation layer 6 includes a base layer 6A and a plurality of different refractive index regions 6B having different refractive indices from the base layer 6A. When an XYZ orthogonal coordinate system having a thickness direction of the phase modulation layer 6 as a Z-axis direction is set and a square lattice of a virtual lattice constant a is set in an XY plane, each of the different refractive index regions 6B is disposed so that a centroid position G thereof is shifted from a lattice point position in a virtual square lattice by a distance r, and the distance r is 0<r?0.3a.

Abstract: A polarization field assisted DUV-LED including a bottom substrate and a n-contact/injection layer formed on the bottom substrate. The n-contact/injection layer includes: a first region for accommodating strain relaxation; a second region for lateral access with a low sheet resistance and higher conductivity compared to the first region to minimize resistive losses and heat generation; and a third region of a graded vertical injection layer with low vertical resistance to minimize heat loss due to vertical resistance. The DUV-LED also includes a p-contact region, and an emitting active region between the n-contact/injection layer and the p-contact region. The injection of electrons and holes into quantum wells proceeds due to tunneling of electrons and holes under the barriers due to less than 2 nm thickness of barriers. This carrier injection lowers the Turn ON voltage of LEDs and reduces heat generation.

Abstract: A semiconductor light emitting device includes: a light emitting part for emitting ultraviolet light; and a coating part that coats an extraction surface from which the ultraviolet light emitted by the light emitting part is extracted. The coating part includes a resin matrix having a refractive index lower than a refractive index of an inorganic material forming the extraction surface and a hollow part that lowers a refractive index of the coating part as a whole by being dispersed in the resin matrix. The hollow part has an average particle diameter smaller than a peak wavelength of the ultraviolet light emitted by the light emitting part.

Abstract: The present disclosure provides a method and structure for producing large area gallium and nitrogen engineered substrate members configured for the epitaxial growth of layer structures suitable for the fabrication of high performance semiconductor devices. In a specific embodiment the engineered substrates are used to manufacture gallium and nitrogen containing devices based on an epitaxial transfer process wherein as-grown epitaxial layers are transferred from the engineered substrate to a carrier wafer for processing. In a preferred embodiment, the gallium and nitrogen containing devices are laser diode devices operating in the 390 nm to 425 nm range, the 425 nm to 485 nm range, the 485 nm to 550 nm range, or greater than 550 nm.

Abstract: Optical devices having a structured active region configured for selected wavelengths of light emissions are disclosed.

Abstract: Embodiments related to emissive devices for displays are discussed. Some embodiments include light emitting diodes including an electron transport layer core having a tube shape with an inner and an outer sidewall, an emission layer on the inner and outer sidewalls, and a hole transport layer on the emission layer, displays and systems including such light emitting diodes, and methods for fabricating them. Other embodiments include emissive laser devices having an emission layer between a hole transport layer and an electron transport layer and first and second metasurface mirrors adjacent to the hole transport layer and the electron transport layer, respectively, displays and systems including such emissive laser devices, and methods for fabricating them.

Abstract: A VCSEL is described that provides for emission from the substrate side. The VCSEL comprises a substrate having first and second major surfaces, a first distributed Bragg reflector (DBR) on the first major surface of the substrate, an active region on the first DBR, and a second DBR on the active region. These elements are aligned on a longitudinal axis along which laser radiation is emitted. In an illustrative embodiment of the invention, an open region extends through the substrate along the longitudinal axis between the second major surface of the substrate and the first DBR. An anti-reflection coating and a first ohmic contact are located on the first DBR in this region. Preferably the first ohmic contact extends around all or part of the anti-reflection coating. A second ohmic contact is located on the surface of the second DBR. The two DBRs form a laser cavity; and emission takes place along the longitudinal axis through the anti-reflection coating. A method for forming the VCSEL is also described.

Abstract: A low voltage laser device having an active region configured for one or more selected wavelengths of light emissions.

Abstract: A low voltage laser device having an active region configured for one or more selected wavelengths of light emissions.

Abstract: A seed crystal substrate 8 includes a base body 1 and a plurality of rows of stripe-shaped seed crystal layers 3 formed on the base body 1. An upper face 3a of the seed crystal layer 3 is (11-22) plane, a groove 4 is formed between the adjacent seed crystal layers 3, and a longitudinal direction of the groove 4 is a direction in which a c-axis of a crystal forming the seed crystal layer is projected on the upper face. A nitride of a group 13 element is formed on the seed crystal substrate.

Abstract: An optoelectronic device grown on a miscut of GaN, wherein the miscut comprises a semi-polar GaN crystal plane (of the GaN) miscut x degrees from an m-plane of the GaN and in a c-direction of the GaN, where ?15<x<?1 and 1<x<15 degrees.

Abstract: A periodic table Group 13 metal nitride crystals grown with a non-polar or semi-polar principal surface have numerous stacking faults. The purpose of the present invention is to provide a period table Group 13 metal nitride crystal wherein the occurrence of stacking faults of this kind are suppressed. The present invention achieves the foregoing by a periodic table Group 13 metal nitride crystal being characterized in that, in a Qx direction intensity profile that includes a maximum intensity and is derived from an isointensity contour plot obtained by x-ray reciprocal lattice mapping of (100) plane of the periodic table Group 13 metal nitride crystal, a Qx width at 1/300th of peak intensity is 6×10?4 rlu or less.

Abstract: A method for providing (Al,Ga,In)N thin films on Ga-face c-plane (Al,Ga,In)N substrates using c-plane surfaces with a miscut greater than at least 0.35 degrees toward the m-direction. Light emitting devices are formed on the smooth (Al,Ga,In)N thin films. Devices fabricated on the smooth surfaces exhibit improved performance.

Abstract: A polarization combiner includes: a base member that includes a body portion, an arm portion extending from the body portion, and a notch portion surrounded with the body portion and the arm portion; a polarization rotating element that is fixed to the arm portion of the base member and that rotates a polarization direction of a first polarized wave; and a polarization combining element that is fixed to the base member so as to face the notch portion of the base member and the polarization rotating element, the polarization combining element combining two polarized waves entering from a surface facing the notch portion and the polarization rotating element, the two polarized waves including the first polarized wave whose polarization direction is rotated by the polarization rotating element and a second polarized wave passing the notch portion.

Abstract: An optical device includes a gallium and nitrogen containing substrate comprising a surface region configured in a (20-2-1) orientation, a (30-3-1) orientation, or a (30-31) orientation, within +/?10 degrees toward c-plane and/or a-plane from the orientation. Optical devices having quantum well regions overly the surface region are also disclosed.

Abstract: A flip chip type laser diode includes a first substrate, a first semiconductor layer disposed on the first substrate, an emitting layer disposed on one part of the first semiconductor layer, a second semiconductor layer disposed on the emitting layer and forming a ridge mesa, a current conducting layer disposed on another part of the first semiconductor layer, a patterned insulating layer covering the second semiconductor layer and the current conducting layer and including a first zone and a second zone which respectively expose a part of the current conducting layer and a part of the second semiconductor layer, a first electrode and a second electrode respectively disposed on the first zone and the second zone. A projection of the ridge mesa projected to the first substrate covers a part of projections of the first electrode and the second electrode projected to the first substrate.

Abstract: A group III nitride semiconductor laser device includes a laser structure, an insulating layer, an electrode and dielectric multilayers. The laser structure includes a semiconductor region on a semi-polar primary surface of a hexagonal group III nitride semiconductor support base. The dielectric multilayers are on first and second end-faces for the laser cavity. The c-axis of the group III nitride tilts by an angle ALPHA from the normal axis of the primary surface in the waveguide axis direction from the first end-face to the second end-faces. A pad electrode has first to third portions provided on the first to third regions of the semiconductor regions, respectively. An ohmic electrode is in contact with the third region through an opening of the insulating layer. The first portion has a first arm, which extends to the first end-face edge. The third portion is away from the first end-face edge.

Abstract: A semiconductor device includes: a semiconductor substrate made of a hexagonal Group III nitride semiconductor and having a semi-polar plane; and an epitaxial layer formed on the semi-polar plane of the semiconductor substrate and including a first cladding layer of a first conductive type, a second cladding layer of a second conductive type, and a light-emitting layer formed between the first cladding layer and the second cladding layer, the first cladding layer being made of Inx1Aly1Ga1-x1-y1N, where x1>0 and y1>0, the second cladding layer being made of Inx2Aly2Ga1-x2-y2N, where0?x2?about 0.02 and about 0.03?y2?about 0.07.

Abstract: Provided is a multi-beam semiconductor laser device in which deterioration of element characteristics is suppressed even when a beam pitch is reduced. The multi-beam semiconductor laser device includes: a first semiconductor multilayer in which a plurality of semiconductor layers are laminated; a plurality of light emitting ridge portions that are formed on the first semiconductor multilayer; a support electrode portion formed in a region between a pair of neighboring light emitting ridge portions; and a front ridge portion formed on the front side of the support electrode portion. The support electrode portion is electrically connected to one of the pair of neighboring light emitting ridge portions. The support electrode portion is higher than the one light emitting ridge portion. An end of the front ridge portion on the front end surface side is higher than the one light emitting ridge portion at the front end surface.

Abstract: Gallium and nitrogen containing optical devices operable as laser diodes are disclosed. The devices include a gallium and nitrogen containing substrate member, which may be semipolar or non-polar. The devices include a chip formed from the gallium and nitrogen substrate member. The chip has a width and a length. The devices have a cavity oriented substantially parallel to the length of the chip, a dimension of less than 120 microns characterizing the width of the chip, and a pair of etched facets configured on the cavity of the chip. The pair of etched facets includes a first facet configured at a first end of the cavity and a second facet configured at a second end of the cavity.

Abstract: Laser devices are presented in which a graphene saturable absorber and an optical amplifier are disposed in a resonant optical cavity with an optical or electrical pump providing energy to the optical amplifier.

Abstract: A surface emitting laser array includes a light emitting unit having a lower reflection mirror, a resonator structure including an active layer, and an upper reflection mirror laminated on a substrate; an electrode for the light emitting unit; a wiring member that establishes electrical connection between the light emitting unit and the electrode; and the substrate on which more than one of the light emitting units, the electrodes, and the wiring members are arranged. The light emitting unit has anisotropic internal stress, and the distance between the center of a first light emitting unit and the center line of the corresponding wiring member is arranged to be different from the distance between the center of a second light emitting unit and the center line of the corresponding wiring member so that variations in the polarization directions of the light emitting units may be within a predetermined range.

Abstract: Optical devices having a structured active region configured for selected wavelengths of light emissions are disclosed.

Abstract: Blue laser diode (LD) structures are grown on a particular subset of semi-polar GaN substrate orientations that offer a distinct set of advantages relative to both (0001), non-polar oriented devices, and alternative semipolar-polar oriented devices operating in the blue regime are disclosed. In particular, the (30-3-1) and (30-31) gallium and nitrogen containing surface orientation and equivalent planes show narrower luminescence spectra than equivalent devices grown on the nonpolar {10-10} m-plane or semipolar planes tilted away from m-plane toward the c-plane between angles of about 0 degrees to about 7 or 8 degrees such as {60-6-1).

Abstract: To improve characteristics of a semiconductor device (semiconductor laser), an active layer waveguide (AWG) comprised of InP is formed over an exposed part of a surface of a substrate having an off angle ranging from 0.5° to 1.0° in a [1-1-1] direction from a (100) plane to extend in the [0-1-1] direction. A cover layer comprised of p-type InP is formed over the AWG with a V/III ratio of 2000 or more. Thereby, it is possible to obtain excellent multiple quantum wells (MQWs) by reducing a film thickness variation of the AWG. Moreover, the cover layer having side faces where a (0-11) plane almost perpendicular to a substrate surface mainly appears can be formed. A sectional shape of a lamination part of the cover layer and the AWG becomes an approximately rectangular shape. Therefore, an electrification region can be enlarged and it is possible to reduce a resistance of the semiconductor device.

Abstract: An optical device includes a gallium and nitrogen containing substrate comprising a surface region configured in a (20-2-1) orientation, a (30-3-1) orientation, or a (30-31) orientation, within +/?10 degrees toward c-plane and/or a-plane from the orientation. Optical devices having quantum well regions overly the surface region are also disclosed.

Abstract: Laser devices formed on a semipolar surface region of a gallium and nitrogen containing material are disclosed. The laser devices have a laser stripe configured to emit a laser beam having a cross-polarized emission state.

Abstract: A photonic-crystal surface-emitting laser (PCSEL) includes a gain medium electromagnetically coupled to a photonic crystal whose energy band structure exhibits a Dirac cone of linear dispersion at the center of the photonic crystal's Brillouin zone. This Dirac cone's vertex is called a Dirac point; because it is at the Brillouin zone center, it is called an accidental Dirac point. Tuning the photonic crystal's band structure (e.g., by changing the photonic crystal's dimensions or refractive index) to exhibit an accidental Dirac point increases the photonic crystal's mode spacing by orders of magnitudes and reduces or eliminates the photonic crystal's distributed in-plane feedback. Thus, the photonic crystal can act as a resonator that supports single-mode output from the PCSEL over a larger area than is possible with conventional PCSELs, which have quadratic band edge dispersion. Because output power generally scales with output area, this increase in output area results in higher possible output powers.

Abstract: A III-nitride semiconductor laser device including: a laser structure including a support base and a semiconductor region, the support base including a hexagonal III-nitride semiconductor and having a semipolar primary surface, and the semiconductor region being provided on the semipolar primary surface of the support base; and an electrode provided on the semiconductor region of the laser structure, the semiconductor region including a first cladding layer, a second cladding layer, and an active layer.

Abstract: Provided is a III-nitride semiconductor laser diode which is capable of lasing at a low threshold. A support base has a semipolar or nonpolar primary surface. The c-axis Cx of a III-nitride is inclined relative to the primary surface. An n-type cladding region and a p-type cladding region are provided above the primary surface of the support base. A core semiconductor region is provided between the n-type cladding region and the p-type cladding region. The core semiconductor region includes a first optical guide layer, an active layer, and a second optical guide layer. The active layer is provided between the first optical guide layer and the second optical guide layer. The thickness of the core semiconductor region is not less than 0.5 ?m. This structure allows the confinement of light into the core semiconductor region without leakage of light into the support base, and therefore enables reduction in threshold current.

Abstract: A group-III nitride semiconductor laser device comprises: a laser structure including a semiconductor region and a support base having a semipolar primary surface of group-III nitride semiconductor; a first reflective layer, provided on a first facet of the region, for a lasing cavity of the laser device; and a second reflective layer, provided on a second facet of the region, for the lasing cavity. The laser structure includes a laser waveguide extending along the semipolar surface. A c+ axis vector indicating a <0001> axial direction of the base tilts toward an m-axis of the group-III nitride semiconductor at an angle of not less than 63 degrees and less than 80 degrees with respect to a vector indicating a direction of an axis normal to the semipolar surface. The first reflective layer has a reflectance of less than 60% in a wavelength range of 525 to 545 nm.

Abstract: A degree of polarization control device includes: a calcium fluoride crystal substrate for transmitting a laser beam; a polarization monitor for measuring the degree of polarization of a laser beam transmitted through the calcium fluoride crystal substrate; and a controller for controlling the rotation angle of the calcium fluoride crystal substrate according to the degree of polarization measured by the polarization monitor; the calcium fluoride crystal substrate being formed by a flat plate having a laser beam entering surface and a laser beam exiting surface running in parallel with the (111) crystal face, the Brewster angle being selected for the incident angle, the rotation angle around the [111] axis operating as a central axis being controlled by the controller.

Abstract: A method for improving the growth morphology of (Ga,Al,In,B)N thin films on nonpolar or semipolar (Ga,Al,In,B)N substrates, wherein a (Ga,Al,In,B)N thin film is grown directly on a nonpolar or semipolar (Ga,Al,In,B)N substrate or template and a portion of the carrier gas used during growth is comprised of an inert gas. Nonpolar or semipolar nitride LEDs and diode lasers may be grown on the smooth (Ga,Al,In,B)N thin films grown by the present invention.

Abstract: A nitride semiconductor structure includes: a plurality of crystal growth seed regions formed of a nitride semiconductor, of which the principal surface is an m-plane and which extends to a range that defines an angle of not less than 0 degrees and not more than 10 degrees with respect to an a-axis; and a laterally grown region formed of a nitride semiconductor which has extended in a c-axis direction from each of the plurality of crystal growth seed regions. An S width that is the spacing between adjacent ones of the plurality of crystal growth seed regions is at least 20 ?m.

Abstract: The invention relates to a laser (1) for emitting laser light in the visible spectral range. A rare earth doped anisotropic crystal (2) comprising a 5d-4f transition is arranged within a laser resonator (7, 8), and a pumping light source (3) pumps the crystal (2) for generating laser light in the visible spectral range by using the 5d-4f transition. The 5d-4f transition of the rare earth doped anisotropic crystal comprises an absorption band extending over several nm. Thus, pump light having a wavelength within a relatively broad wavelength range can be used. This reduces the requirements with respect to the wavelength accuracy of the pumping light source and, thus, more pumping light sources of an amount of produced pumping light sources can be used for assembling the laser, thereby reducing the amount of rejects.

Abstract: A nitride semiconductor laser diode comprises a substrate; an n-side nitride semiconductor layer containing an n-type impurity and disposed on the substrate; an active layer having a light emitting layer including InxAlyGa1-x-yN (0<x<1, 0?y<1, and 0<x+y<1) and disposed on the n-side nitride semiconductor layer; and a p-side nitride semiconductor layer containing a p-type impurity and disposed on the active layer. The lasing wavelength of the nitride semiconductor laser diode is 500 nm or greater.

Abstract: A method for growth and fabrication of semipolar (Ga,Al,In,B)N thin films, heterostructures, and devices, comprising identifying desired material properties for a particular device application, selecting a semipolar growth orientation based on the desired material properties, selecting a suitable substrate for growth of the selected semipolar growth orientation, growing a planar semipolar (Ga,Al,In,B)N template or nucleation layer on the substrate, and growing the semipolar (Ga,Al,In,B)N thin films, heterostructures or devices on the planar semipolar (Ga,Al,In,B)N template or nucleation layer. The method results in a large area of the semipolar (Ga,Al,In,B)N thin films, heterostructures, and devices being parallel to the substrate surface.

Abstract: A laser diode device operable at a one or more wavelength ranges. The device has a first waveguide provided on a non-polar or semipolar crystal plane of gallium containing material. In a specific embodiment, the first waveguide has a first gain characteristic and a first direction. In a specific embodiment, the first waveguide has a first end and a second end and a first length defined between the first end and the second end. The device has a second waveguide provided on a non-polar or semipolar crystal plane of gallium containing material. In a specific embodiment, the second waveguide has a second gain characteristic and a second direction. In a specific embodiment, the second waveguide has a first end, a second end, and a second length defined between the first end and the second end.

Abstract: Disclosed is a surface emitting laser device, including a substrate; a lower reflecting mirror provided on the substrate; an active layer provided on the lower reflecting mirror; an upper reflecting mirror provided on the active layer, including an emitting region, laser light being emitted from the emitting region, the upper reflecting mirror being formed by alternately laminating dielectrics, refracting indices of the dielectrics being different from each other; and an adjusting layer formed of semiconductor, provided in the emitting region between the active layer and the upper reflecting mirror, a shape of the adjusting layer in a plane parallel to a surface of the substrate including shape anisotropy in two mutually perpendicular directions.

Abstract: A laser device is disclosed that provides at least an ultraviolet laser beam and preferably both an ultraviolet laser beam and a visible laser beam. The laser device includes a semiconductor laser device (e.g. a laser diode) to generate visible laser light which is coupled into a frequency doubling crystal taking the form of a single crystal thin film frequency-doubling waveguide structure. The single crystal thin film frequency-doubling waveguide converts a portion of the visible light emitted by the laser diode into ultraviolet light. Both visible and ultraviolet laser light is emitted from the waveguide. As an example, the single crystal thin film frequency-doubling frequency doubling waveguide includes a frequency doubling crystal region composed of ?-BaB2O4 (?-BBO), a cladding region composed of materials that are transparent or nearly transparent at the wavelength of the ultraviolet laser light beam and a supporting substrate composed of any material.

Abstract: An illuminating device includes at least first and second nitride-based semiconductor light-emitting elements each having a semiconductor chip with an active layer region. The active layer region is at an angle of 1° or more with an m plane, and an angle formed by a normal line of a principal surface in the active layer region and a normal line of the m plane is 1° or more and 5° or less. The first and second nitride-based semiconductor light-emitting elements have thicknesses of d1 and d2, respectively, and emit the polarized light having wavelengths ?1 and ?2, respectively, where the inequalities of ?1<?2 and d1<d2 are satisfied.

Abstract: An (Al,In,B,Ga)N or III-nitride based laser diode epitaxially grown on orientations other than a c-plane orientation, namely various semipolar and nonpolar orientations, and having polished facets. The semipolar orientation may be a semipolar (11-22), (11-2-2), (101-1), (10-1-1), (20-21), (20-2-1), (30-31) or (30-3-1) orientation, and the nonpolar orientation may be a nonpolar (10-10) or (11-20) orientation. The facets are chemically mechanically or mechanically polished.

Abstract: A disclosed surface emitting laser device includes an oscillator structure including an active layer, semiconductor multilayer reflection mirrors sandwiching the oscillator structure, an electrode provided on an emitting surface where light is emitted in a manner such that the electrode surrounds an emitting region, and a dielectric film formed in at least one region outside a center part of the emitting region so that a refractive index of the region outside the center part of the emitting region is less than the refractive index of the center part of the emitting region. When viewed from an emitting direction of the light, a part of the electrode overlaps a part of the dielectric film.

Abstract: According to example embodiments, a hybrid vertical cavity laser for a photonic integrated circuit (PIC) includes: a grating mirror between first and second low refractive index layers, an optical waveguide optically coupled to one side of the grating mirror, a III-V semiconductor layer including an active layer on an upper one of the first and second low refractive index layers, and a top mirror on the III-V semiconductor layer. The grating mirror includes a plurality of bar-shaped low refractive index material portions arranged parallel to each other. The low refractive index material portions include a plurality of first portions having a first width and a plurality of second portions having second width in a width direction. The first and second widths are different.

Abstract: Provided is a group-III nitride semiconductor laser device with a laser cavity allowing for a low threshold current, on a semipolar surface of a support base in which the c-axis of a hexagonal group-III nitride is tilted toward the m-axis. First and second fractured faces 27, 29 to form the laser cavity intersect with an m-n plane. The group-III nitride semiconductor laser device 11 has a laser waveguide extending in a direction of an intersecting line between the m-n plane and the semipolar surface 17a. For this reason, it is feasible to make use of emission by a band transition enabling the low threshold current. In a laser structure 13, a first surface 13a is opposite to a second surface 13b. The first and second fractured faces 27, 29 extend from an edge 13c of the first surface 13a to an edge 13d of the second surface 13b. The fractured faces are not formed by dry etching and are different from conventionally-employed cleaved facets such as c-planes, m-planes, or a-planes.