Abstract: A fluid analyzer includes a substrate, a quantum cascade laser formed on a surface of the substrate and including a first light-emitting surface and a second light-emitting surface facing each other in a predetermined direction parallel to the surface, a quantum cascade detector formed on the surface and including the same layer structure as the quantum cascade laser and a light incident surface facing the second light-emitting surface in the predetermined direction, and an optical element disposed on an optical path of light emitted from the first light-emitting surface across an inspection region in which a fluid to be analyzed is to be disposed and reflecting the light to feed the light back to the first light-emitting surface.

Abstract: A dental therapy apparatus which enables a dental therapy more surely and less invasively is provided. A dental therapy apparatus (10A) comprises a laser light source (11) emitting laser light (L) having a wavelength within a wavelength region of 5.7 to 6.6 ?m; a controller (12) pulse-driving the laser light source and controlling at least one of pulse width and repetition frequency of pulsed laser light emitted from the laser light source; and an irradiation optical system for irradiating a tooth (20) including a carious part (21) with the light emitted from the laser light source. In this dental therapy apparatus, the controller controls at least one of the pulse width and repetition frequency of the pulsed light, so as to selectively cut the carious part (21).

Abstract: A quantum cascade laser device has a light-absorbing cover member located between one emission end face of a quantum cascade laser element and an emission window of a housing. The emission end face and an opposing surface of a submount with respect to the cover member are flush with each other. The cover member has an opening at a position opposing the emission end face. The opening has a tapered first opening part increasing its diameter from the emission end face side to the emission window side and a second opening part formed with a fixed diameter not smaller than the smallest diameter of the first opening part.

Abstract: A wavelength variable light source includes a housing, a heat sink disposed in the housing, an excitation light source disposed on the heat sink and configured to output excitation light, a gain medium disposed on the heat sink and including an active layer and a lower DBR, a MEMS mechanism including a movable film facing the gain medium via a gap, disposed on the gain medium, and configured to control the gap, an upper DBR provided in the movable film and configuring a resonator together with the lower DBR, a reflector configured to reflect the excitation light output from the excitation light source toward the gain medium in the housing, and a window formed in the housing and configured to transmit light output from the gain medium.

Abstract: A quantum cascade laser is configured with a semiconductor substrate, and an active layer provided on a first surface of the substrate and having a cascade structure in the form of a multistage lamination of unit laminate structures each of which includes an emission layer and an injection layer. The active layer is configured to be capable of generating first pump light of a frequency ?1 and second pump light of a frequency ?2 by intersubband emission transitions of electrons, and to generate output light of a difference frequency ? by difference frequency generation from the first pump light and the second pump light. Grooves respectively formed in a direction intersecting with a resonating direction in a laser cavity structure are provided on a second surface opposite to the first surface of the substrate.

Abstract: A quantum cascade laser is configured with a semiconductor substrate, and an active layer provided on a first surface of the substrate and having a multistage lamination of unit laminate structures each of which includes an emission layer and an injection layer. The active layer is configured to be capable of generating first pump light of a frequency ?1 and second pump light of a frequency ?2, and to generate output light of a difference frequency ? by difference frequency generation. An external diffraction grating is provided constituting an external cavity for generating the first pump light and configured to be capable of changing the frequency ?1, outside an element structure portion including the active layer. Grooves respectively formed in a direction intersecting with a resonating direction are provided on a second surface of the substrate.

Abstract: A quantum cascade detector includes a semiconductor substrate; an active layer having a cascade structure; a lower cladding layer provided between the active layer and the substrate and having a lower refractive index than the active layer; a lower metal layer provided between the lower cladding layer and the substrate; an upper cladding layer provided on an opposite side to the substrate with respect to the active layer and having a lower refractive index than the active layer; and an upper metal layer provided on an opposite side to the active layer with respect to the upper cladding layer. A first end face being in a waveguide direction in a waveguide structure with the active layer, lower cladding layer, and upper cladding layer is an entrance surface for light to be detected.

Abstract: A quantum cascade laser is configured with a semiconductor substrate, and an active layer having a multistage lamination of emission layers and injection layers. The active layer is configured to be capable of generating first pump light of a frequency ?1 and second pump light of a frequency ?2, and to generate output light of a difference frequency ? by difference frequency generation. An external diffraction grating is provided for generating the first pump light, outside an element structure portion including the active layer, and an internal diffraction grating is provided for generating the second pump light, inside the element structure portion. The frequency ?2 is set to be fixed to a frequency not coincident with a gain peak, and the frequency ?1 is set to be variable to a frequency different from the frequency ?2.

Abstract: A fluid analyzer includes a substrate, a quantum cascade laser formed on a surface of the substrate and including a first light-emitting surface and a second light-emitting surface facing each other, a first quantum cascade detector formed on the surface and including the same layer structure as the quantum cascade laser and a first light incident surface facing the first light-emitting surface, a second quantum cascade detector formed on the surface and including the same layer structure as the quantum cascade laser and a second light incident surface facing the second light-emitting surface, and a resin member covering at least the second light-emitting surface and the second light incident surface and having optical transparency and an electrical insulation property. A first space in which a fluid to be analyzed is disposed is provided in a first area between the first light-emitting surface and the first light incident surface.

Abstract: A movable diffraction grating includes: a support portion; a movable portion swingably connected to the support portion; a coil buried in the movable portion; a magnetic field generator configured to apply a magnetic field to the coil; an insulation layer provided on a surface of the movable portion; a resin layer provided on the insulation layer and provided with a diffraction grating pattern; and a reflection layer formed of a metal and provided on the resin layer to follow the diffraction grating pattern.

Abstract: Organic photoelectric conversion element has a first electrode, a photoelectric conversion layer, and a second electrode. The photoelectric conversion layer has a first organic layer that contains a first organic semiconductor containing principally a p-type organic semiconductor, a second organic layer that contains a second organic semiconductor containing principally an n-type organic semiconductor, and an intermediate layer that contains the first organic semiconductor and the second organic semiconductor. The second organic layer is disposed at a side of the second electrode relative to the first organic layer. The intermediate layer is between the first organic layer and the second organic layer and reaches each of these layers. The thickness of the second organic layer is greater than the sum of the thicknesses of the first organic layer and intermediate layer.

Abstract: A quantum cascade detector includes a semiconductor substrate; an active layer having a cascade structure; a lower cladding layer provided between the active layer and the substrate and having a lower refractive index than the active layer; a lower metal layer provided between the lower cladding layer and the substrate; an upper cladding layer provided on an opposite side to the substrate with respect to the active layer and having a lower refractive index than the active layer; and an upper metal layer provided on an opposite side to the active layer with respect to the upper cladding layer. A first end face being in a waveguide direction in a waveguide structure with the active layer, lower cladding layer, and upper cladding layer is an entrance surface for light to be detected.

Abstract: A fluid analyzer includes a substrate, a quantum cascade laser formed on a surface of the substrate and including a first light-emitting surface and a second light-emitting surface facing each other, a first quantum cascade detector formed on the surface and including the same layer structure as the quantum cascade laser and a first light incident surface facing the first light-emitting surface, a second quantum cascade detector formed on the surface and including the same layer structure as the quantum cascade laser and a second light incident surface facing the second light-emitting surface, and a resin member covering at least the second light-emitting surface and the second light incident surface and having optical transparency and an electrical insulation property. A first space in which a fluid to be analyzed is disposed is provided in a first area between the first light-emitting surface and the first light incident surface.

Abstract: A quantum cascade laser manufacturing method includes: a step of pressing a mother stamper against a resin film having flexibility to make a resin stamper 201 having a second groove pattern P2; a step of making a wafer with an active layer formed on a semiconductor substrate; a step of forming a resist film 304 on a surface on the active layer side of the wafer; a step of pressing the resin stamper against the resist film 304 by air pressure to form a third groove pattern P3 on the resist film 304; and a step of etching the wafer with the resist film 304 serving as a mask to form a diffraction grating on a surface of the wafer.

Abstract: A quantum cascade laser is configured with a semiconductor substrate, and an active layer provided on a first surface of the substrate and having a multistage lamination of unit laminate structures each of which includes an emission layer and an injection layer. The active layer is configured to be capable of generating first pump light of a frequency ?1 and second pump light of a frequency ?2, and to generate output light of a difference frequency ? by difference frequency generation. An external diffraction grating is provided constituting an external cavity for generating the first pump light and configured to be capable of changing the frequency ?1, outside an element structure portion including the active layer. Grooves respectively formed in a direction intersecting with a resonating direction are provided on a second surface of the substrate.

Abstract: A quantum cascade laser is configured with a semiconductor substrate, and an active layer having a multistage lamination of emission layers and injection layers. The active layer is configured to be capable of generating first pump light of a frequency ?1 and second pump light of a frequency ?2, and to generate output light of a difference frequency ? by difference frequency generation. An external diffraction grating is provided for generating the first pump light, outside an element structure portion including the active layer, and an internal diffraction grating is provided for generating the second pump light, inside the element structure portion. The frequency ?2 is set to be fixed to a frequency not coincident with a gain peak, and the frequency ?1 is set to be variable to a frequency different from the frequency ?2.

Abstract: A quantum cascade laser is configured with a semiconductor substrate, and an active layer provided on a first surface of the substrate and having a cascade structure in the form of a multistage lamination of unit laminate structures each of which includes an emission layer and an injection layer. The active layer is configured to be capable of generating first pump light of a frequency ?1 and second pump light of a frequency ?2 by intersubband emission transitions of electrons, and to generate output light of a difference frequency ? by difference frequency generation from the first pump light and the second pump light. Grooves respectively formed in a direction intersecting with a resonating direction in a laser cavity structure are provided on a second surface opposite to the first surface of the substrate.

Abstract: A quantum cascade laser is configured with a semiconductor substrate and first and second active layers provided in series on the substrate. A unit laminate structure of the first active layer has a subband level structure having an emission upper level and an emission lower level, and is configured so as to be able to generate light of a first frequency ?1, a unit laminate structure of the second active layer has a subband level structure having a first emission upper level, a second emission upper level, and a plurality of emission lower levels, and is configured so as to be able to generate light of a second frequency ?2, and light of a difference frequency ? is generated by difference frequency generation from the light of the first frequency ?1 and the light of the second frequency ?2.

Abstract: A quantum cascade laser is configured with a semiconductor substrate and first and second active layers provided in series on the substrate. A unit laminate structure of the first active layer has a subband level structure having an emission upper level and an emission lower level, and is configured so as to be able to generate light of a first frequency ?1, a unit laminate structure of the second active layer has a subband level structure having a first emission upper level, a second emission upper level, and a plurality of emission lower levels, and is configured so as to be able to generate light of a second frequency ?2, and light of a difference frequency ? is generated by difference frequency generation from the light of the first frequency ?1 and the light of the second frequency ?2.

Abstract: A quantum cascade laser includes a semiconductor substrate, and an active layer being provided on the substrate, and having a cascade structure in which quantum well emission layers and injection layers are alternately laminated, and the laser has a base portion including the substrate, and a stripe-shaped ridge portion including the active layer. Further, a reflection control film is formed from a ridge end face over a base end face on an end face in a resonating direction of the laser, and, on the base end face, for a second side and a third side adjacent to a first side on the ridge portion side of the base end face, and a fourth side facing the first side, the reflection control film is formed on a region other than regions near those three sides with predetermined widths.