Abstract: A photodetector includes: a semiconductor substrate; a mesa portion formed on a major surface of the semiconductor substrate to extend along an optical waveguide direction; a first contact layer; a second contact layer; a first electrode; and an air bridge wiring electrically connected to the first contact layer and the first electrode. When viewed in a direction perpendicular to the major surface of the semiconductor substrate, a length of the mesa portion in the optical waveguide direction is longer than a length of the mesa portion in a direction perpendicular to the optical waveguide direction. The air bridge wiring is led out from the first contact layer to one side in the direction perpendicular to the optical waveguide direction, and is bridged between the first contact layer and the first electrode.

Abstract: A beating spectroscopy device includes: first and second quantum cascade lasers; a quantum cascade detector; and a sample holder configured to hold a sample on an optical path between the second quantum cascade laser and the quantum cascade detector. Lights from the first and second quantum cascade lasers are detected by the quantum cascade detector while a wavelength of the light from the second quantum cascade laser is changed to scan a frequency of a beating signal having a frequency in accordance with a wavelength difference between the lights from the first and second quantum cascade lasers.

Abstract: A semiconductor light emitting element includes a semiconductor stack and an electrode portion. The semiconductor stack includes an active layer and a phase modulation layer. The phase modulation layer has a plurality of phase modulation regions. Each of the phase modulation regions includes a base region having a first refractive index, and a plurality of different refractive index regions that have a second refractive index different from the first refractive index and are distributed two-dimensionally. The electrode portion includes a plurality of electrodes that respectively overlap the plurality of phase modulation regions when viewed from the stacking direction of the semiconductor stack. The plurality of electrodes are electrically isolated from each other. Laser light resonated in each of the plurality of phase modulation regions is emitted through a second surface. The semiconductor light emitting element has a reflection reduction structure configured to reduce reflection of the light.

Abstract: An optical device of one embodiment outputs light in a short-wavelength range such as a visible range. The optical device includes a UC layer, first and second light-confinement layers, and a resonance mode forming layer. The UC layer contains an upconversion material receiving excitation light in a first wavelength range and outputting light in a second wavelength range. The first light-confinement layer has a characteristic of reflecting part of the second wavelength-range light. The second light-confinement layer has a characteristic of reflecting part of the second wavelength-range light and transmitting the remainder, and is disposed such that the UC layer locates between the first and second light-confinement layers. The resonance mode forming layer locates between the UC layer and the first or second light-confinement layer, includes a base layer and plural modified refractive index regions, and forms a resonance mode of the second wavelength-range light.

Abstract: A semiconductor light-emitting device includes a plurality of unit light-emitting elements, in which the unit light-emitting elements each include a stacked structure including a substrate, an active layer, a phase modulation layer including a base region having a first refractive index and a plurality of different refractive index regions two-dimensionally distributed in the base region with a second refractive index, a plurality of light emission regions configured to emit laser light generated by mode formation of the light incident on the phase modulation layer from the active layer to outside, and a first electrode and a second electrode having polarities different from each other, the stacked structures in the plurality of unit light-emitting elements are independent of each other, and the plurality of unit light-emitting elements is two-dimensionally arranged in a state of being separated from each other to constitute a light-emitting element array.

Abstract: The laser module includes a QCL element and a support member. The QCL element has a first end surface located on a first side in a second direction orthogonal to a stacking direction and a second end surface located on a second side opposite to the first side in the second direction. The substrate has first to fourth substrate-surfaces. The support member has a first portion having a first surface facing at least a portion of the fourth substrate-surface, and a second portion having a second surface facing at least a portion of the first substrate-surface and a third surface located opposite to the second surface in the second direction. At least a part of the terahertz wave generated in the active layer is incident on the second surface of the support member through the substrate and is emitted from the third surface through the inside of the second portion.

Abstract: A photodetection module includes a photodetector and a fixing member. The photodetector includes a semiconductor substrate, a mesa portion, a first contact layer, a second contact layer, and a first electrode formed in a planar shape on a major surface of the semiconductor substrate, and electrically connected to one of the first contact layer and the second contact layer. The fixing member includes an insulating substrate, and a first wiring formed in a planar shape on a major surface of the insulating substrate. A recessed portion is formed in the major surface of the insulating substrate, and at least a part of the mesa portion is disposed inside the recessed portion. The first electrode is electrically connected to the first wiring in a state where the first electrode is in surface contact with the first wiring.

Abstract: A laser module includes a support substrate, a QCL element, a resin layer, and an emission direction defining portion. The QCL element includes a substrate that has a front surface for emitting a terahertz wave and a semiconductor multilayer structure that includes an active layer generating the terahertz wave. The emission direction defining portion is provided on an upper surface of the resin layer and is configured to emit the terahertz wave, which is emitted from the front surface of the substrate, to the outside from the upper surface. The resin layer contacts the front surface of the substrate and extends in a front-rear direction when viewed in a vertical direction. The height position of the upper surface of the resin layer with respect to the support surface of the support substrate reaches at least the height position of the upper surface of the substrate.

Abstract: A quantum cascade laser includes a semiconductor substrate having a first surface and a second surface, a semiconductor stacked body that includes an active layer having a cascade structure and is formed on the first surface, a first electrode formed a surface of the semiconductor stacked body, and a second electrode formed on the second surface. The semiconductor substrate is an InP substrate with a carrier density of 1×1017 cm?3 or less. A concave portion that passes through the semiconductor substrate and reaches the semiconductor stacked body is formed in the second surface. The second electrode is continuously formed on the second surface of the semiconductor substrate, on side surfaces of the concave portion, and on an exposed surface of the semiconductor stacked body which is exposed from the semiconductor substrate at the bottom of the concave portion.

Abstract: A sintered body of the present invention includes cerium oxide and cerium fluoride or yttrium fluoride.

Abstract: A sintered body of the present invention includes cerium oxide and cerium fluoride or yttrium fluoride.

Abstract: The light-emitting element of an embodiment outputs a clear optical image while suppressing light output efficiency reduction, and includes a substrate, a light-emitting unit, and a bonding layer. The light-emitting unit has a semiconductor stack, including a phase modulation layer, between first and second electrodes. The phase modulation layer has a base layer and modified refractive index regions, and includes a first region having a size including the second electrode, and a second region. Each gravity center of the second region's modified refractive index region is arranged by an array condition. The light from the stack is a single beam, and regarding a first distance from the substrate to the stack's front surface and a second distance from the substrate to the stack's back surface, a variation amount of the first distance along a direction on the substrate is smaller than a variation amount of the second distance.

Abstract: A thermally fused board manufacturing apparatus includes: a fiberizing section that produces a fiber material by fiberizing a raw material containing fabric; a material supply pipe section that carries the fiber material; a humidifying section configured to humidify the fiber material; a carriage pipe section that adds a material different from the fiber material to the fiber material and carries the material and the fiber material; a mixing section that produces a deposition fiber material by mixing the material and the fiber material, at part of the carriage pipe section; a depositing section that forms a fiber aggregate by depositing the deposition fiber material; a thermal fusing section that forms a thermally fused board by applying heat and pressure to the fiber aggregate; and a controller that controls the humidifying section.

Abstract: A web forming apparatus includes a drum portion and a second web forming unit. The drum portion has an accommodating chamber capable of accommodating fragments, and accommodating powder supplied from a first supplying unit. The second web forming unit forms a second web by letting a mixture containing the fragments and the powder falling from the drum portion accumulate. The first supplying unit includes a storing chamber for storing the powder and an outlet portion provided below the storing chamber. The powder goes out of the storing chamber via the outlet portion. The drum portion has meshes formed in a net demarcating the accommodating chamber. The powder is able to pass through the meshes. The outlet portion is provided vertically over the net of the drum portion.

Abstract: Provided is a mushroom cultivation medium that easily maintains its shape and that is easy to handle. The mushroom cultivation medium includes cellulose fibers, a binder binding the cellulose fibers to each other, and wood chips mixed with the cellulose fibers.

Abstract: A photodetection module includes a photodetector and a fixing member. The photodetector includes a semiconductor substrate, a mesa portion, a first contact layer, a second contact layer, and a first electrode formed in a planar shape on a major surface of the semiconductor substrate, and electrically connected to one of the first contact layer and the second contact layer. The fixing member includes an insulating substrate, and a first wiring formed in a planar shape on a major surface of the insulating substrate. A recessed portion is formed in the major surface of the insulating substrate, and at least a part of the mesa portion is disposed inside the recessed portion. The first electrode is electrically connected to the first wiring in a state where the first electrode is in surface contact with the first wiring.

Abstract: The laser module includes a QCL element and a support member. The QCL element has a first end surface located on a first side in a second direction orthogonal to a stacking direction and a second end surface located on a second side opposite to the first side in the second direction. The substrate has first to fourth substrate-surfaces. The support member has a first portion having a first surface facing at least a portion of the fourth substrate-surface, and a second portion having a second surface facing at least a portion of the first substrate-surface and a third surface located opposite to the second surface in the second direction. At least a part of the terahertz wave generated in the active layer is incident on the second surface of the support member through the substrate and is emitted from the third surface through the inside of the second portion.

Abstract: A photodetector includes: a semiconductor substrate; a mesa portion formed on a major surface of the semiconductor substrate to extend along an optical waveguide direction; a first contact layer; a second contact layer; a first electrode; and an air bridge wiring electrically connected to the first contact layer and the first electrode. When viewed in a direction perpendicular to the major surface of the semiconductor substrate, a length of the mesa portion in the optical waveguide direction is longer than a length of the mesa portion in a direction perpendicular to the optical waveguide direction. The air bridge wiring is led out from the first contact layer to one side in the direction perpendicular to the optical waveguide direction, and is bridged between the first contact layer and the first electrode.

Abstract: The laser module includes a QCL element, a diffraction grating unit including a movable diffraction grating, a first lens that transmits light emitted from an end surface of the QCL element and light returning from the movable diffraction grating to the QCL element, a second lens that transmits terahertz waves emitted from the QCL element, a first holder, and a package. The first holder has a support surface on which the QCL element is mounted and a side surface connected to the support surface and facing the first lens in a resonance direction. A distance from an intersection point between the side surface and the support surface to the end surface along the resonance direction is smaller than a distance between the intersection point and the first lens along the resonance direction.