Abstract: In a semiconductor laser device, a supply path that guides a cooling fluid supplied from a supply port side, toward a disposition region, spray holes that spray the cooling fluid guided by the supply path, from below the disposition region, and a discharge path that guides the cooling fluid sprayed from the spray holes, toward a discharge port are provided within a body portion of a heat sink. The spray holes are disposed along a resonance direction of a semiconductor laser element disposed in the disposition region, and the discharge path extends in a direction intersecting with the resonance direction of the semiconductor laser element disposed in the disposition region.

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 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: 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 quantum-cascade laser element includes: a semiconductor substrate; a semiconductor mesa formed on the semiconductor substrate to include an active layer having a quantum-cascade structure and to extend along a light waveguide direction; an embedding layer formed to interpose the semiconductor mesa along a width direction of the semiconductor substrate; a cladding layer formed over the semiconductor mesa and over the embedding layer; and a metal layer formed on the cladding layer. A pair of groove portions extending along the light waveguide direction are formed in a surface on an opposite side of the cladding layer from the semiconductor substrate. The pair of groove portions are disposed in two respective outer regions when the cladding layer is equally divided into four regions in the width direction of the semiconductor substrate. The metal layer enters the pair of groove portions.

Abstract: A quantum-cascade laser element includes: a semiconductor substrate; a semiconductor laminate formed on the semiconductor substrate to include a ridge portion configured to include an active layer having a quantum-cascade structure; an embedding layer including a first portion formed on a side surface of the ridge portion, and a second portion extending from an edge portion of the first portion on a side of the semiconductor substrate along a width direction of the semiconductor substrate; a metal layer formed on a top surface of the ridge portion, on the first portion, and on the second portion; and a dielectric layer disposed between the second portion and the metal layer. The dielectric layer is formed such that a part of the second portion is exposed from the dielectric layer. The metal layer is in contact with the second portion at the part.

Abstract: The laser module includes a QCL element, a diffraction grating unit, a first lens holder, a second lens holder, and a mount member. The fourth mounting portion of the mount member is provided with a placement hole into which the protruding portion of the diffraction grating unit is inserted. The placement hole is longer than the protruding portion so that the protruding portion can be slid in the X-axis direction relative to the placement hole. A wall surface for positioning the diffraction grating unit is provided between the third mounting portion and the fourth mounting portion. The diffraction grating unit includes a positioning surface facing the wall surface. The diffraction grating unit is fixed to the fourth mounting portion in a state where the protruding portion is inserted into the placement hole and the positioning surface is in surface contact with the wall surface.

Abstract: The laser module includes a QCL element, a diffraction grating unit, a first lens holder, a second lens holder, and a mount member. The first mounting portion has a first top surface on which the first lens holder is mounted via an adhesive layer. The third mounting portion has a third top surface on which the second lens holder is mounted via an adhesive layer. The second mounting portion has a second top surface located higher than the first top surface and the third top surface, a first side surface connecting the second top surface and the first top surface, and a second side surface connecting the second top surface and the third top surface. A notch extending from the second top surface to the first top surface or the third top surface is formed in at least one of the first side surface and the second side surface.

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: An external resonance-type laser module includes: a quantum cascade laser; a MEMS diffraction grating including a movable portion capable of swinging around an axis and a diffraction grating portion formed on the movable portion; and a lens. The diffraction grating portion includes a plurality of lattice grooves arranged in a first direction and each of the plurality of lattice grooves extends in a second direction perpendicular to the first direction. The MEMS diffraction grating is disposed such that a normal line of the diffraction grating portion is inclined with respect to an end surface and the first direction is along a lamination direction of a laminated structure when viewed in a direction perpendicular to the end surface. A length of the diffraction grating portion in the first direction exceeds a length of the diffraction grating portion in the second direction.

Abstract: The laser module includes a QCL element, a MEMS diffraction grating, a lens holder for holding a lens disposed between the QCL element and the MEMS diffraction grating, and a package. The package includes a bottom wall, a side wall erected on the bottom wall and formed in an annular shape so as to surround a region in which the QCL element is accommodated, and a top wall closing an opening of the side wall on a side opposite to a side where the bottom wall is disposed. The top wall faces the bottom wall in a direction orthogonal to the optical axis direction of the lens, and the distance between the top wall and a surface of the lens holder on a side where the top wall is disposed is smaller than a thickness of the lens holder along the optical axis direction of the lens.

Abstract: The laser module includes a QCL element, a MEMS diffraction grating, a first lens holder disposed on a side opposite to a side on which the MEMS diffraction grating is disposed with respect to the QCL element, a second lens holder disposed between the QCL element and the MEMS diffraction grating, a package, an electrode terminal disposed along an inner wall surface of the package, and a wire for electrically connecting the electrode terminal and the QCL element. An end portion of the wire on a side where the QCL element is disposed is disposed at a position between the first lens holder and the second lens holder when viewed from a direction orthogonal to a facing direction in which the first lens holder and the second lens holder face each other.

Abstract: The laser module includes a QCL element, a MEMS diffraction grating, a lens holder holding a lens disposed between the QCL element and the MEMS diffraction grating, a package, an electrode terminal disposed along an inner wall surface of the package, and a wire for electrically connecting the electrode terminal and a coil. The top wall of the package faces the bottom wall of the package in a direction orthogonal to the optical axis direction of the lens. The MEMS diffraction grating includes an electrode pad electrically connected to the coil. The electrode pad is connected to the electrode terminal via the wire. A height position of the electrode pad with respect to the bottom wall is equal to or higher than a height position of the electrode terminal with respect to the bottom wall.

Abstract: An external resonance-type laser module includes: a quantum cascade laser; a MEMS diffraction grating including a movable portion capable of swinging around an axis and a diffraction grating portion formed on the movable portion; a lens; a magnet; and a yoke. The MEMS diffraction grating includes a pair of coils respectively disposed on one side and the other side with respect to the axis when viewed in a normal direction parallel to a normal line of the diffraction grating portion, and each of the pair of coils includes an inside part extending along the axis. A recess portion is formed in the magnet, and at least a part of the recess portion overlaps the inside part when viewed in the normal direction.

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: An optical semiconductor element includes a semiconductor substrate, a first laminated structure provided on a front surface of the semiconductor substrate, and a second laminated structure provided on the front surface of the semiconductor substrate, the first laminated structure includes a first quantum cascade region, the second laminated structure includes a dummy region having the same layer structure as the first quantum cascade region, a second quantum cascade region provided on the front surface of the semiconductor substrate via the dummy region, and one of the first quantum cascade region and the second quantum cascade region is a quantum cascade laser, and the other of the first quantum cascade region and the second quantum cascade region is a quantum cascade detector.