Abstract: A method of generating a single photon, includes preparing an optical resonator including a resonator mode of a resonance angular frequency ?c, preparing a material contained in the optical resonator, including a low energy state |g> and a high energy state |e>, and including a transition angular frequency ?a between |g>?|e> that is varied by an external field, applying, to the material, light of an angular frequency ?l different from the resonance angular frequency ?c, and applying a first external field to the material to vary the transition angular frequency ?a to resonate with the angular frequency ?l, such that a state of the material is changed to |e>, and then applying a second external field to the material to vary the transition angular frequency ?a to resonate with the resonance angular frequency ?c, such that the state of the material is restored to |g>.

Abstract: Provided are a nitride semiconductor laser chip with a reliability improved by relieving stress due to strain within the nitride semiconductor laser chip, a manufacturing method thereof, and a nitride semiconductor laser device. The nitride semiconductor laser chip comprises: a substrate; and a laminated structure provided on a main surface of the substrate and including a nitride semiconductor layer. In the laminated structure, at least one crack parallel to a resonator end face is formed. By forming a crack within a laser chip, stress due to strain is relieved; therefore, it is possible to obtain a laser chip having a high reliability.

Abstract: Optical microcavity arrangements and approaches facilitate a variety of applications. According to an example embodiment of the present invention, an optical microcavity arrangement includes a microcrystal structure having a plurality of optical cavities therein to facilitate the control of light. Emitters such as colloidal quantum dots are optically coupled to the optical cavities by attaching or otherwise arranging a material, which includes the emitters, to the optical microcavity arrangement. In many applications, the emitters couple photons of a wavelength in a range of wavelengths selectively passed by the optical cavities, and are amenable to operation at relatively high temperatures (e.g., at about room temperature or higher), which is useful for a variety of applications.

Abstract: A nitride semiconductor laser device includes: a substrate made of silicon in which a plane orientation of a principal surface is a {100} plane; and a semiconductor laminate that includes a plurality of semiconductor layers formed on the substrate and includes a multiple quantum well active layer, each of the plurality of semiconductor layers being made of group III-V nitride. The semiconductor laminate has a plane parallel to a {011} plane which is a plane orientation of silicon as a cleavage face and the cleavage face constructs a facet mirror.

Abstract: The object of this invention is to provide a high-output type nitride light emitting device. The nitride light emitting device comprises an n-type nitride semiconductor layer or layers, a p-type nitride semiconductor layer or layers and an active layer therebetween, wherein a gallium-containing nitride substrate is obtained from a gallium-containing nitride bulk single crystal, provided with an epitaxial growth face with dislocation density of 105/cm2 or less, and A-plane or M-plane which is parallel to C-axis of hexagonal structure for an epitaxial face, wherein the n-type semiconductor layer or layers are formed directly on the A-plane or M-plane. In case that the active layer comprises a nitride semiconductor containing In, an end face film of single crystal AlxGa1-xN (0?x?1) can be formed at a low temperature not causing damage to the active layer.

Abstract: It is made possible to provide an optical waveguide system that has a coupling mechanism capable of selecting a wavelength and has the highest possible conversion efficiency, and that is capable of providing directivity in the light propagation direction. An optical waveguide system includes: a three-dimensional photonic crystalline structure including crystal pillars and having a hollow structure inside thereof; an optical waveguide in which a plurality of metal nanoparticles are dispersed in a dielectric material, the optical waveguide having an end portion inserted between the crystal pillars of the three-dimensional photonic crystalline structure, and containing semiconductor quantum dots that are located adjacent to the metal nanoparticles and emit near-field light when receiving excitation light, the metal nanoparticles exciting surface plasmon when receiving the near-field light; and an excitation light source that emits the excitation light for exciting the semiconductor quantum dots.

Abstract: A semiconductor laser device, which has a protective film at an end surface thereof, is adaptable to demands for higher outputs or shorter wavelengths. The semiconductor laser device according to the present invention includes a dielectric film on at least one end surface of an optical resonator, in which the dielectric film includes a first dielectric layer and a second dielectric layer comprised of the same elements and disposed in sequence from the end surface side of the semiconductor, the first dielectric layer including a layer made of a single crystal material and the second dielectric layer including a layer made of an amorphous material.

Abstract: A polycrystalline transparent ceramic article including lutetium is presented. The article includes an oxide with a formula of ABO3, having type A lattice sites and type B lattice sites. The lattice site A may further comprise a plurality of elements, in addition to lutetium. Type B lattice site includes aluminum. An imaging device, a laser assembly, and a scintillator including the lutetium-based article is provided. A method of making the above article is also provided.

Abstract: A bar-shaped semiconductor laser chip that can hold down a variation in oscillation wavelength is provided. The bar-shaped semiconductor laser chip has a nitride semiconductor substrate and a semiconductor layer formed on the main surface of the nitride semiconductor substrate and including a plurality of laser chip portions. The plurality of laser chip portions are arrayed in the [11-20] direction. The main surface of the nitride semiconductor substrate is a (0001) plane having an off-angle in the direction along the [11-20] direction. The central part of the main surface of the nitride semiconductor substrate has an off-angle of 0.05±0.1 degrees from the (0001) plane in the direction along the [11-20] direction.

Abstract: A nitride semiconductor laser element, comprises; nitride semiconductor layers in which a nitride semiconductor layer of a first conduction type, an active layer, and a nitride semiconductor layer of a second conduction type that is different from the first conduction type are laminated in that order; a cavity end face formed by the nitride semiconductor layers; and a protective film formed on the cavity end face, the protective film has a region in which an axial orientation of crystals is different in the direction of lamination of the nitride semiconductor layers.

Abstract: This semiconductor laser device includes a substrate, a green semiconductor laser element, formed on a surface of the substrate, including a first active layer having a first major surface of a semipolar plane and a blue semiconductor laser element, formed on a surface of the substrate, including a second active layer having a second major surface of a surface of the semipolar plane, while the first active layer includes a first well layer having a compressive strain and having a thickness of at least about 3 nm, and the second active layer includes a second well layer having a compressive strain.

Abstract: The present invention provides a nitride semiconductor laser element, comprising: a nitride semiconductor structure having a first nitride semiconductor layer, a second nitride semiconductor layer, and an active layer provided between the first and second nitride semiconductor layers; a cavity end face provided to the nitride semiconductor structure; and a protective film having a hexagonal crystal structure, and having a first region provided on a first crystal surface of the nitride semiconductor structure in the cavity end face and a second region provided on a second crystal surface in the surface of at least one of the first and second nitride semiconductor layer, the first and second regions of the protective film are oriented in the same axial direction as that of the respective first and second crystal surfaces.

Abstract: A nitride semiconductor laser diode includes: a substrate made of silicon in which a plane orientation of a principal surface is a {100} plane; and a semiconductor that includes a plurality of semiconductor layers formed on the substrate and including an active layer, each of the plurality of semiconductor layers being made of group III nitride. The semiconductor has a plane parallel to a {011} plane which is a plane orientation of silicon as a cleaved facet, the cleaved facet forming a facet mirror.

Abstract: A semiconductor laser device includes a multilayer structure made of group III nitride semiconductors formed on a substrate. The multilayer structure includes a MQW active layer, and also includes a step region selectively formed in an upper portion thereof. In another upper portion of the multilayer structure, a ridge stripe portion including a waveguide, which extends in parallel to a principal surface of the multilayer structure, is formed. In the vicinity of the step region, a first region, in which the MQW active layer has a bandgap energy of Eg1, is formed, and a second region, which is adjacent to the first region and in which the MQW active layer has a bandgap energy of Eg2 (Eg2<Eg1), is formed. The waveguide, which is formed so as to include the first and second regions and so as not to include the step region, performs self-oscillation.

Abstract: A current blocking structure of a semiconductor laser includes a p-type InP buried layer, an n-type InP current blocking layer, and a p-type InP current blocking layer laminated along the mesa side surface of a ridge. In the structure, an upper end part of the n-type InP current blocking layer is covered with the p-type InP buried layer and the p-type InP current blocking layer. The n-type InP current blocking layer is prevented from contacting n-type and p-type InP cladding layers. Creation of an ineffective current path from one of the n-type InP cladding layers through the n-type InP current blocking layer to a p-type InP cladding layer of the semiconductor laser is prevented.

Abstract: A nitride semiconductor laser element comprises; a nitride semiconductor layer that includes a first nitride semiconductor layer, an active layer, and a second nitride semiconductor layer, and that has a cavity with end faces, and a protective film formed on at least one end face of the cavity, wherein the protective film is formed of a first film with a crystal structure that has the same axial orientation as that of the nitride semiconductor layer constituting the end face of the cavity, and a second film with a crystal structure that has a different axial orientation from that of the first film, in this order from the side of the end face.

Abstract: It is intended to improve operation characteristics of a nitride-based semiconductor light-emitting device including a nitride-based semiconductor crystal substrate having a main surface of a non-polarity plane. A nitride-based semiconductor light-emitting device includes a nitride-based semiconductor crystal substrate and semiconductor stacked-layer structure of crystalline nitride-based semiconductor formed on a main surface of the substrate, wherein the semiconductor staked-layer structure includes an active layer sandwiched between an n-type layer and a p-type layer, the main surface of the substrate has a crystallographic plane tilted from a {10-10} plane of the nitride-based semiconductor crystal by an angle of more than ?0.5° and less than ?0.05° or more than +0.05° and less than +0.5° about a <0001> axis.

Abstract: A semiconductor laser including: a nitride III-V compound semiconductor substrate configured to have a first planar area, a second planar area, and a third planar area in a major surface, the first planar area being formed of a C-plane, the second planar area being continuous with the first planar area and being formed of a semipolar plane inclined to the first planar area, the third planar area being continuous with the second planar area and being formed of a C-plane parallel to the first planar area; a first cladding layer configured to be composed of a nitride III-V compound semiconductor on the major surface of the nitride III-V compound semiconductor substrate; an active layer configured to be composed of a nitride III-V compound semiconductor that exists on the first cladding layer and contains In; and a second cladding layer configured to be composed of a nitride III-V compound semiconductor on the active layer.

Abstract: In a surface emitting laser element, on an inclined substrate, a resonator structural body including an active layer, and a lower semiconductor DBR and an upper semiconductor DBR sandwiching the resonator structural body are stacked. A shape of a current passing-through region in an oxide confinement structure of the upper semiconductor DBR is symmetrical to an axis passing through a center of the current passing-through region parallel to an X axis and symmetrical to an axis passing through the center of the current passing-through region parallel to a Y axis, and a thickness of an oxidized layer surrounding the current passing-through region is greater in the +Y direction than in the +X and ?X directions. An opening width of a light outputting section in the X axis direction is smaller than another opening width of the light outputting section in the Y axis direction.

Abstract: A disclosed surface-emitting laser includes a substrate and multiple semiconductor layers stacked on the substrate. A normal of the principal plane of the substrate is inclined with respect to one of crystal orientations <1 0 0> toward one of crystal orientations <1 1 1>. The semiconductor layers include a resonator structure including an active layer; and a semiconductor multilayer mirror stacked on the resonator structure. The semiconductor multilayer mirror includes a confined structure where a current passage area is surrounded by an oxidized area including at least an oxide generated by oxidation of a part of a selective oxidation layer containing aluminum. A strain field caused by the oxidation is present at least in a part of the vicinity of the oxidized area. In the strain field, the amount of strain in a first axis direction is different from the amount of strain in a second axis direction.

Abstract: A surface-emission laser diode of a vertical-cavity surface-emission laser structure includes a substrate and a mesa structure formed on the substrate, the mesa structure including therein a current confinement structure, wherein the current confinement structure includes a conductive current confinement region and an insulation region surrounding the conductive current confinement region, the insulation region being an oxide of a semiconductor material forming the conductive current confinement region, and wherein a center of the current confinement region is offset from a center of the mesa structure in a plane perpendicular to a laser oscillation direction.

Abstract: A nitride-based semiconductor laser device includes a nitride-based semiconductor layer formed on a main surface of a substrate and having an emission layer, wherein the nitride-based semiconductor layer includes a first side surface formed by a (000-1) plane and a second side surface inclined with respect to the first side surface, and a ridge having an optical waveguide extending perpendicular to a [0001] direction in an in-plane direction of the main surface of the substrate is formed by a region held between the first side surface and the second side surface.

Abstract: A small-sized and high-efficiency light emitting device capable of easily emitting green light includes a resonator including a photonic crystal having a refractive-index periodic structure and a point defect member formed in the photonic crystal to disturb the refractive-index periodic structure, and an active member provided inside the resonator and formed by an In containing nitride semiconductor, wherein a wavelength determined by a band gap energy of the active member is included in a photonic band gap range of the photonic crystal, and is set to be shorter than a peak wavelength at a shortest-wavelength side of a resonance mode of the resonator in the photonic band gap range.

Abstract: This invention provides a process for producing a gallium nitride-based compound semiconductor laser element, characterized in that a plane inclined at not less than 0.16 degree and not more than 5.0 degrees in terms of absolute value in the direction of <1-100> in (0001) Ga plane, or a plane in which the root mean square of (A2+B2) is not less than 0.17 and not more than 7.0 wherein A represents the off angle of (0001) Ga plane to <1-100> direction and B represents the off angle of (0001) Ga plane to <11-20> direction, is used as a crystal growth plane of a gallium nitride substrate, and an active layer is grown at a growth rate of not less than 0.5 ú/sec and not more than 5.0 ú/sec.

Abstract: An integrated semiconductor laser device capable of improving the properties of a laser beam and reducing the cost for optical axis adjustment is provided. This integrated semiconductor laser device comprises a first semiconductor laser element including a first emission region and having either a projecting portion or a recess portion and a second semiconductor laser element including a second emission region and having either a recess portion or a projecting portion. Either the projecting portion or the recess portion of the first semiconductor laser element is fitted to either the recess portion or the projecting portion of the second semiconductor laser element.

Abstract: A resonator is provided which is produced by a defect formed in a three-dimensional photonic crystal. The three-dimensional photonic crystal can include layers containing a plurality of columnar structures with discrete structures in sublayers.

Abstract: In a nitride semiconductor laser device so structured as to suppress development of a step on nitride semiconductor layers, the substrate has the (11-20) plane as the principal plane, the resonator end surface is perpendicular to the principal plane, and, in the cleavage surface forming the resonator end surface, at least by one side of a stripe-shaped waveguide, an etched-in portion is formed as an etched-in region open toward the surface of the nitride semiconductor layers.

Abstract: In a nitride semiconductor laser chip so structured as to suppress development of a step on nitride semiconductor layers, the substrate has the (1-100) plane as the principal plane, the resonator facet is perpendicular to the principal plane, and, in the cleavage surface forming the resonator facet, at least by one side of a stripe-shaped waveguide, an etched-in portion is formed as an etched-in region open toward the surface of the nitride semiconductor layers.

Abstract: A laser medium includes a single crystal of chromium-doped LiScl-xInxGe1-ySiyO4, where 0?x?1 and 0?y?1. Preferably, x and y are not both 0. A laser, such as a tunable near infrared laser, can contain the laser medium.

Abstract: A surface emitting laser device can further improve the light emission efficiency thereof to enlarge the degree of freedom of the device. The surface emitting laser device includes an active layer 103, a photonic crystal layer disposed to be adjacent to the active layer, an electrode 108 disposed on the photonic crystal layer, and a plurality of light emitting regions regulated by the electrode. The photonic crystal layer is configured to include a first photonic crystal region 104 disposed just under the electrode, and having a periodic refractive index structure for resonance of light within a plane, and a second photonic crystal region 105 disposed just under the light emitting region, and having a periodic refractive index structure for emitting light in a direction perpendicular to the plane.

Abstract: An inventive semiconductor laser diode includes a Group III nitride semiconductor layered structure having a major crystal growth plane defined by a non-polar or semi-polar-plane. The Group III nitride semiconductor layered structure includes: a p-type cladding layer and an n-type cladding layer; an In-containing p-type guide layer and an In-containing n-type guide layer held between the p-type cladding layer and the n-type cladding layer; and an In-containing light emitting layer held between the p-type guide layer and the n-type guide layer.

Abstract: An optical element includes a surface-emitting type semiconductor laser, and a light-receiving element that detects a part of laser light emitted from the surface-emitting type semiconductor laser, wherein the light-receiving element is formed above the surface-emitting type semiconductor laser and includes a semiconductor layer having one or more layers, and at least one of the layers in the semiconductor layer has a plane configuration that has anisotropy.

Abstract: A bipolar quantum cascade (QC) laser includes a p-n junction disposed adjacent to an active/injection region of semiconductor layers. Systems that make use of such QC lasers and methods for manufacturing such QC lasers are also described.

Abstract: A nitride semiconductor laser element has a first nitride semiconductor layer, an active layer, a second nitride semiconductor layer, and a first protective film in contact with a cavity end face of the nitride semiconductor layer, wherein the first protective film in contact with at least the active layer of the cavity end face has a region thinner than the maximum thickness of the first protective film.

Abstract: The present invention provides a nitride semiconductor laser element, comprising: a nitride semiconductor structure having a first nitride semiconductor layer, a second nitride semiconductor layer, and an active layer provided between the first and second nitride semiconductor layers; a cavity end face provided to the nitride semiconductor structure; and a protective film having a hexagonal crystal structure, and having a first region provided on a first crystal surface of the nitride semiconductor structure in the cavity end face and a second region provided on a second crystal surface in the surface of at least one of the first and second nitride semiconductor layer, the first and second regions of the protective film are oriented in the same axial direction as that of the respective first and second crystal surfaces.

Abstract: A nitride semiconductor laser device includes, on a first principle face of the (0001) of a nitride semiconductor substrate, a nitride semiconductor layer having a first conductivity type, an active layer, and a nitride semiconductor layer having a second conductivity type that is different from the first conductivity type, and being formed a stripe ridge on the surface thereof. The (000-1) face and an inclined face other than the (000-1) face are exposed on a second principal face of the nitride semiconductor substrate. The inclined face other than the (000-1) face represents no less than 0.5% over the surface area of the second principal face.

Abstract: A nitride semiconductor laser element comprises; a nitride semiconductor layer that includes a first nitride semiconductor layer, an active layer, and a second nitride semiconductor layer, and that has a cavity with end faces, and a protective film formed on at least one end face of the cavity, wherein the protective film is formed of a first film with a crystal structure that has the same axial orientation as that of the nitride semiconductor layer constituting the end face of the cavity, and a second film with a crystal structure that has a different axial orientation from that of the first film, in this order from the side of the end face.

Abstract: A method for fabricating a semiconductor device includes dividing an off substrate so that a first edge face, the off substrate having an operation layer on a main surface of the off substrate, and cutting the off substrate to form a second edge face crossing the first edge face so that an entire surface of the second edge face is closer to a direction vertical to the main surface of the off substrate than a surface cleaved along with the second edge face.

Abstract: A nitride semiconductor laser diode includes: a substrate made of silicon in which a plane orientation of a principal surface is a {100} plane; and a semiconductor that includes a plurality of semiconductor layers formed on the substrate and including an active layer, each of the plurality of semiconductor layers being made of group III nitride. The semiconductor has a plane parallel to a {011} plane which is a plane orientation of silicon as a cleaved facet, the cleaved facet forming a facet mirror.

Abstract: A semiconductor laser element having a structure in which at least one AlGaInP or GaInP layer is formed above a GaAs substrate. The crystal orientation of the principal plane of the GaAs substrate is tilted from (100) toward (111). When the total thickness of the at least one AlGaInP or GaInP layer is 1 micrometer or smaller, the tilt angle of the crystal orientation of the principal face is 8 to 54.7 degrees. When the total thickness of the at least one AlGaInP or GaInP layer is 1 micrometer or greater, the tilt angle of the crystal orientation of the principal face is 13 to 54.7 degrees.

Abstract: A nitride semiconductor light-emitting device includes a nitride semiconductor substrate of which at least part of a surface is formed from a nitride semiconductor and a nitride film semiconductor growth layer laid on the surface of the nitride semiconductor substrate. A carved region in the shape of a depressed portion may be formed on the surface of the nitride semiconductor substrate. The carved region may have an inverted tapered shape or a tapered shape in cross-section. Alternatively, or additionally, the nitride film semiconductor growth layer may include a gallium nitride film or an aluminum containing gallium nitride film where the nitride film semiconductor growth layer makes contact with the nitride semiconductor substrate. Alternatively, or additionally, the nitride film semiconductor growth layer may include a light-emitting portion formed at a location 20 ?m or more away from the carved region.

Abstract: This semiconductor laser device has the same structure as the conventional broad-area type semiconductor laser device, except that both side regions of light emission areas of active and clad layers are two-dimensional-photonic-crystallized. The two-dimensional photonic crystal formed on both side regions of the light emission area is the crystal having the property that 780 nm laser light cannot be wave-guided in a resonator direction parallel to a striped ridge within the region. The light traveling in the direction can exist only in the light emission area sandwiched between two photonic crystal regions, which results in the light laterally confined by the photonic crystal region. The optical confinement of the region suppresses the loss in the light at both edges of the stripe serving as the boundary of the optical confinement, which reduces the curve of wave surface and uniforms the light intensity distributions of NFP and FFP.

Abstract: On a plate of birefringent crystal made of an LiNbO3 crystal or an LiTaO3 crystal, a conductive substance is adhered to the whole periphery of side surfaces of the plate that intersect an incident surface of a laser beam, thereby to form a wave plate. A polarizer is provided at the latter stage of the wave plate. A wavelength is monitored based on an output from the polarizer. With this arrangement, based on the use of the LiNbO3 crystal or the LiTaO3 crystal that can be manufactured by a large quantity at low cost, it is possible to obtain polarization characteristics and wavelength discrimination characteristics that are stable against environmental changes such as temperature and external stress, by suppressing the pyroelectric effect and the piezoelectric effect of these materials.

Abstract: An n-type GaN layer is grown onto a sapphire substrate and a hexagonal etching mask is formed onto the n-type GaN layer as provided. The n-type GaN layer is etched to a predetermined depth by using the etching mask by the RIE method. A hexagonal prism portion whose upper surface is a C plane is formed. After the etching mask was removed, an active layer and a p-type GaN layer are sequentially grown onto the whole surface of the substrate so as to cover the hexagonal prism portion, thereby forming a light emitting device structure. After that, a p-side electrode is formed onto the p-type GaN layer of the hexagonal prism portion and an n-side electrode is formed onto the n-type GaN layer.

Abstract: The invention comprises a composite material comprising a host material in which are incorporated semiconductor nanocrystals. The host material is light-transmissive and/or light-emissive and is electrical chargetransporting thus permitting electrical charge transport to the core of the nanocrystals. The semiconductor nanocrystals emit and/or absorb light in the near infrared spectral range. The nanocrystals cause the composite material to emit/absorb energy in the near infrared (NIR) spectral range, and/or to have a modified dielectric constant, compared to the host material. The invention further comprises electro-optical devices composed of this composite material and a method of producing them. Specifically described are light emitting diodes that emit light in the NIR and photodetectors that absorb light in the same region.

Abstract: In order to achieve a long wavelength, 1.3 micron or above, VCSEL or other semiconductor laser, layers of strained quantum well material are supported by mechanical stabilizers which are nearly lattice matched with the GaAs substrate, or lattice mismatched in the opposite direction from the quantum well material; to allow the use of ordinary deposition materials and procedures. By interspersing thin, unstrained layers of e.g. gallium arsenide in the quantum well between the strained layers of e.g. InGaAs, the GaAs layers act as mechanical stabilizers keeping the InGaAs layers thin enough to prevent lattice relaxation of the InGaAs quantum well material. Through selection of the thickness and width of the mechanical stabilizers and strained quantum well layers in the quantum well, 1.3 micron and above wavelength lasing is achieved with use of high efficiency AlGaAs mirrors and standard gallium arsenide substrates.

Abstract: Provided is a method of forming quantum dots, including: forming a buffer layer on an InP substrate so as to be lattice-matched with the InP substrate; and sequentially alternately depositing In(Ga)As layers and InAl(Ga)As or In(Ga, Al, As)P layers that are greatly lattice-mismatched with each other on the buffer layer so as to form In(Ga, Al)As or In(Ga, Al, P)As quantum dots.

Abstract: A semiconductor laser that has a reflective surface. The reflective surface redirects the light of an edge emitting laser diode to emit from the top or bottom surface of the diode. The laser may include a gain layer and a feedback layer located within a semiconductive die. The gain and feedback layers generate a laser beam that travels parallel to the surface of the die. The reflective surface reflects the laser beam 90 degrees so that the beam emits the die from the top or bottom surface. The reflective surface can be formed by etching a vicinally oriented III-V semiconductive die so that the reflective surface extends along a (111)A crystalline plane of the die.