Abstract: This optical coupler for coupling a plurality of visible light beams having different wavelengths includes: a substrate made of a material different from lithium niobate; and an optical coupling function layer formed on a main surface of the substrate. The optical coupling function layer includes: two multimode-interference-type optical coupling parts; optical-input-side waveguides and an optical-output-side waveguide connected to one multimode-interference-type optical coupling part, and optical-input-side waveguides and an optical-output-side waveguide connected to the other multimode-interference-type optical coupling part. The multimode-interference-type optical coupling parts, the optical-input-side waveguides, and the optical-output-side waveguides are made of a lithium niobate film.

Abstract: A transceiver device includes: a receiving device including a magnetic element having a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, wherein the receiving device is configured to receive an optical signal; a transmission device including a modulated light output element, wherein the transmission device is configured to transmit an optical signal; and a circuit chip including an integrated circuit electrically connected to the magnetic element and the modulated light output element.

Abstract: An optical modulation element is provided with a substrate, a waveguide layer formed on the substrate, a dielectric layer formed on the waveguide layer, and an electrode formed on the dielectric layer. An outer peripheral end portion of the dielectric layer has an offset area positioned inside an outer peripheral end portion of the substrate. In at least a part of the offset area, a distance from the outer peripheral end portion of the substrate to the outer peripheral end portion of the dielectric layer is equal to or less than a distance from the outer peripheral end portion of the substrate to the outer peripheral end portion of the electrode.

Abstract: A transceiver device includes: a receiving device including a magnetic element having a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, wherein the receiving device is configured to receive an optical signal; a transmission device including a modulated light output element, wherein the transmission device is configured to transmit an optical signal; and a circuit chip including an integrated circuit electrically connected to the magnetic element and the modulated light output element.

Abstract: This optical modulator includes an optical modulation element having a first optical waveguide, a second optical waveguide, a first electrode configured to apply an electric field to the first optical waveguide, and a second electrode configured to apply an electric field to the second optical waveguide; and a control unit configured to control an applied voltage between the first electrode and the second electrode. The control unit sets Vpp to 0.06×V??Vpp?0.4×V? when a half-wavelength voltage of the optical modulation element is V? and an applied voltage width that is an amplitude of an applied voltage applied to the optical modulation element is Vpp, and sets Vn?Vmin?Vn+0.29×V? or Vn?0.29×V??Vmax?Vn when a minimum value and a maximum value of a voltage applied to the optical modulation element are respectively Vmin and Vmax and a null point voltage of the optical modulation element is Vn.

Abstract: A light source unit (1000) of the present disclosure includes a light source part (100), a first electrical signal generating device (40-1) configured to control current that drives an optical semiconductor device (30), an optical modulator (200) having a Mach-Zehnder type optical waveguide (10) and an electrode configured to apply an electric field to the optical waveguide (10), and a second electrical signal generating device (40-2) configured to control a voltage that operates the optical modulator (200), the first electrical signal generating device (40-1) and the second electrical signal generating device (40-2) are synchronizably connected to each other, and intensity of light emitted from the optical modulator (200) is changed by the current controlled by the first electrical signal generating device (40-1) and the voltage controlled by the second electrical signal generating device (40-2).

Abstract: An optical circuit element capable of preventing stray light propagated through a part including a substrate of the optical circuit element from being emitted to the outside is provided. The optical circuit element has a substrate, an optical waveguide layer that is formed on one surface of the substrate, and a protective layer that is overlaid on the optical waveguide layer. The optical waveguide layer has an optical waveguide configured for light to be propagated therethrough. A groove portion, which reaches to a position deeper than the one surface from a surface of the protective layer toward the substrate, is formed. The optical circuit element further includes a light absorption layer that covers at least a bottom surface and a side surface of the groove portion.

Abstract: The optical modulator includes an optical modulation element having a first optical waveguide, a second optical waveguide, a first electrode which applies an electric field to the first optical waveguide, and a second electrode which applies an electric field to the second optical waveguide, and a control unit configured to control an applied voltage between the first electrode and the second electrode. When a half-wave voltage of the optical modulation element is V? and a null point voltage of the optical modulation element is Vn, the control unit sets an operating point Vd in a range of Vn+0.50V??Vd?Vn+0.75V? or Vn?0.75V??Vd?Vn?0.50V? and sets an applied voltage width Vpp, which is an amplitude of an applied voltage applied to the optical modulation element, in a range of 0.22V??Vpp?0.50V?.

Abstract: This optical modulation element includes a first optical waveguide, a second optical waveguide, a first electrode for applying an electric field to the first optical waveguide, and a second electrode for applying an electric field to the second optical waveguide. The first optical waveguide and the second optical waveguide each include a ridge-shaped portion protruding from a first surface of a lithium niobate film. A first interaction length L1 that is a length of a part of the first electrode overlapping the first optical waveguide in a longitudinal direction is 0.9 mm or more and 20 mm or less. A second interaction length L2 that is a length of a part of the second electrode overlapping the second optical waveguide in the longitudinal direction is 0.9 mm or more and 20 mm or less.

Abstract: An optical device that includes at least one magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer; a substrate; and a waveguide is provided, wherein the waveguide and the magnetic element are located on or above the substrate, and wherein at least some of light propagating in the waveguide is applied to the magnetic element.

Abstract: A optical modulation element includes a substrate made of a material different from lithium niobate, a lithium niobate film formed on a main surface of the substrate, the lithium niobate film including a Mach-Zehnder-type optical waveguide having a first ridge and a second ridge that function as a first optical waveguide and a second optical waveguide, respectively, wherein both the first ridge and the second ridge having a cross-sectional shape fixed portion, at least one of the first ridge and the second ridge having a cross-sectional shape non-fixed portion in which the cross-sectional shape is different from that of the cross-sectional shape fixed portion, and the optical output obtained when the DC bias voltage applied between the first electrode and the second electrode is 0 (V) is smaller than the maximum of the optical output obtained when the DC bias voltage is changed in a predetermined voltage range.

Abstract: A transceiver device includes: a receiving device including a magnetic element having a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, wherein the receiving device is configured to receive an optical signal; a transmission device including a modulated light output element, wherein the transmission device is configured to transmit an optical signal; and a circuit chip including an integrated circuit electrically connected to the magnetic element and the modulated light output element.

Abstract: A transmission device of the present disclosure is a transmission device that transmits a visible light signal to a receiving device, and includes a laser light source configured to emit visible light, and an optical modulator configured to change intensity of the visible light and generate a visible light signal, in which the optical modulator has an optical waveguide that serves as a transmission path for the visible light, and the optical waveguide is formed of a material containing lithium niobate.

Abstract: An optical modulator is provided with a ridge-shaped optical waveguide formed of a dielectric thin film having electro-optic effect, a buffer layer covering the optical waveguide, a signal electrode formed on the buffer layer so as to be opposed to the optical waveguide through the buffer layer; a ground electrode formed on the buffer layer together with the signal electrode, and a dielectric film having a higher dielectric constant than air and covering at least a part of exposed surfaces of the signal electrode and ground electrode and exposed surfaces of the buffer layer.

Abstract: An electro-optic device is provided with a Mach-Zehnder optical waveguide including at least one linear section and at least one curved section and a differential RF signal electrode provided along the Mach-Zehnder optical waveguide. Optical input/output ports of the Mach-Zehnder optical waveguide are provided at one end side in a first direction in which the linear section extends. The differential RF signal electrode is provided in both the linear and curved sections.

Abstract: An optical modulator is provided with a substrate, first and second optical waveguides each formed of a ridge-shaped electro-optic material film and disposed so as to be mutually adjacent on the substrate, a buffer layer covering upper surfaces of the first and second optical waveguides, first and second signal electrodes provided above the buffer layer so as to be opposed respectively to the first and second optical waveguides, and a dielectric layer covering at least one of a part of an exposed surface of the first signal electrode and a part of an exposed surface of the second signal electrode, and a part of an upper surface of the buffer layer. Differential signals are applied to the first and second signal electrodes.

Abstract: What provided is a biosensor including: a substrate having a surface with first and second regions adjacent each other; a magnetoresistance effect element disposed on the first region; a soft magnetic thin film on the second region; a protective film disposed on both the first region and the second region, covering a surface of the soft magnetic thin film, and disposed on the top part of the second region and contains an affinity substance recognizing the biomolecule on the outer surface of the second region exclusively; and an MR cover film disposed on at least the top part of the first region, disposed on the protective film above the magnetoresistance effect element, and being free of the affinity substance, wherein the soft magnetic thin film transmits an in-plane component of a stray magnetic field of magnetic beads to the magnetoresistance effect element.

Abstract: A first disclosure is an optical fiber member equipped with two holding members that hold an optical fiber such that an end surface of the optical fiber is located on one end and a curving portion having a coat of the optical fiber is curved to be extended at another end; the holding members are provided with holding flat portions that sandwich an end portion of the optical fiber where the coat is removed such that the end surface of the optical fiber is located on the one end; at least any of the holding flat portions has an aligning groove to fix a position of the end portion of the optical fiber; the holding member is provided with a curved surface at a position adjacent to the curving portion in the extending direction D1; and the two holding members are equal in thermal expansion coefficient.

Abstract: A chemical sensor that enables high detection accuracy that includes a soft-magnetic-material film, a magnetoresistance-effect element, a first film disposed over the soft-magnetic-material film, and a second film disposed over the magnetoresistance-effect element, wherein, when viewed from a direction perpendicular to the film surface of the soft-magnetic-material film, the soft-magnetic-material film is disposed at least partially so as not to overlap the magnetoresistance-effect element; when viewed from the direction perpendicular to the film surface of the soft-magnetic-material film, the magnetoresistance-effect element is disposed at least partially so as not to overlap the soft-magnetic-material film; and the second film has higher solubility in a specific liquid than the first film.

Abstract: To provide a chemical sensor that enables high detection accuracy. A chemical sensor includes a substrate, two or more magnetoresistance-effect elements disposed side by side in a substrate in-plane direction over the substrate, a first film disposed over a region between the magnetoresistance-effect elements adjacent to each other, and a second film disposed over the magnetoresistance-effect elements, wherein the second film has higher solubility in a specific liquid than the first film.