Abstract: An optical device includes a slab layer formed on a lower cladding layer, a core formed on the slab layer, a first metal layer, and a second metal layer. The optical device further includes a first adhesion layer and a second adhesion layer formed between the slab layer on both sides of the core and the first metal layer and the second metal layer. The first metal layer and the second metal layer are formed apart from the core.

Abstract: An optical device includes a cladding layer and a core formed on the cladding layer and including a crystal of a III-V compound semiconductor crystal. The core has a plurality of first regions and second regions periodically connected in series. In addition, adjacent first regions and second regions have reversals of polarization. In the plurality of first regions and second regions included in the core, the adjacent first region and second region have reversals of polarization in a direction perpendicular to a waveguide direction.

Abstract: An embodiment plasmonic waveguide includes a first metal layer formed on a substrate, an electro-optic thin film formed on the first metal layer and including a material having an electro-optic effect, and a second metal layer formed on the electro-optic thin film. In an embodiment, a waveguide region in which the first metal layer and the second metal layer overlap each other in a direction normal to a planar surface of the substrate (layer stacking direction), the waveguide region extending in the planar surface direction of the substrate, is included. For example, the first metal layer and the second metal layer are formed only in the waveguide region, and each of respective widths of the first metal layer and the second metal layer is equal to a width of an overlap between the first metal layer and the second metal layer.

Abstract: Optical alignment between an optical waveguide device and an optical connection part is realized easily and at low cost. An optical circuit in which optical waveguides to be connected to optical fibers are formed includes: an alignment optical waveguide configured to be opposed to, on an optical waveguide edge face to which an optical connection part having guide holes for insertion of core wires of the optical fibers is to be fixed, a guide hole into which an alignment optical fiber is to be inserted; and a light path changing member configured to change a path of light to a vertical direction with respect to the optical axis direction of the core of the alignment optical waveguide.

Abstract: An optical device includes a core formed on a substrate, a first source electrode and a second source electrode formed in contact with both side surfaces of the core interposed between the first source electrode and the second source electrode, and a drain electrode formed in contact with an upper surface of the core. The core, the first source electrode, and the second source electrode together form a plasmonic waveguide. The first source electrode and the second source electrode are Schottky coupled to the core.

Abstract: There is provided an optical connection structure in which an optical fiber and an optical semiconductor waveguide are easily connected with low loss. The present invention relates to an optical connection structure configured to connect an optical waveguide device and an optical fiber including cores having different refractive indexes, wherein an optical connection component using a planar lightwave circuit is bonded and fixed on an end surface of an input/output waveguide of the optical waveguide device, a value of a refractive index of a core of the planar lightwave circuit is between a value of the refractive index of the core of the optical waveguide device and a value of the refractive index of the core of the optical fiber, and the optical waveguide device and the optical fiber are optically connected via the planar lightwave circuit.

Abstract: A core and a slab layer that are formed on a lower clad layer are provided. The lower clad layer is formed on a substrate. The core is comprised of a semiconductor and has a rectangular shape in a cross-sectional view. The slab layer is comprised of a semiconductor. The core and the slab layer have a thickness that allows only up to a secondary mode of light to be present. Further, the core and the slab layer are laminated on the lower clad layer. Further, the core and the slab layer are disposed to be optically coupled to each other.

Abstract: An optical nonlinearity measurement method according to the present disclosure utilizes photon pair generation through a spontaneous four-wave mixing process, to observe photon pairs using an optical waveguide loaded with a two-dimensional material. Compared with the Z-scan method, the influence of free carriers on nonlinear refractive indexes is only indirect. With a parameter being the length of the attached two-dimensional material in the optical waveguide direction, a theoretical value of the coincidence rate of the photon pairs based on the coupled wave equation is fitted to a measured value of the coincidence rate of the photon pairs. For the coincidence rate of the photon pairs, the theoretical value based on the coupled wave equation is fitted to the measured value in a state reflecting the structure of the optical waveguide loaded with the two-dimensional material, and nonlinear coefficients ?1 and ?2 at that time are obtained.

Abstract: An optical modulator includes a core formed above a lower cladding layer and a first metal layer and a second metal layer disposed above the lower cladding layer with the core being interposed in between. The optical modulator also includes an upper cladding layer formed above the lower cladding layer, covering the core, the first metal layer, and the second metal layer. In addition, the optical modulator includes a resistor formed on the upper cladding layer and above the core. The resistor is electrically connected to the first metal layer by a first penetrating wiring line penetrating the upper cladding layer and is electrically connected to the second metal layer by a second penetrating wiring line penetrating the upper cladding layer.

Abstract: A phase shifter includes a first cladding layer, a first core formed on the first cladding layer, and a second core formed on the first core. The first cladding layer and the first core are formed from a first material having an electrooptical effect. The second core is formed from a second material having a refractive index higher than that of the first material. The phase shifter includes a first metal layer and a second metal layer formed on side surfaces of both of the first core and the second core.

Abstract: An embodiment plasmonic waveguide includes a first metal layer formed on a substrate, an electro-optic thin film formed on the first metal layer and including a material having an electro-optic effect, and a second metal layer formed on the electro-optic thin film. In an embodiment, a waveguide region in which the first metal layer and the second metal layer overlap each other in a direction normal to a planar surface of the substrate (layer stacking direction), the waveguide region extending in the planar surface direction of the substrate, is included. For example, the first metal layer and the second metal layer are formed only in the waveguide region, and each of respective widths of the first metal layer and the second metal layer is equal to a width of an overlap between the first metal layer and the second metal layer.

Abstract: Provided is an optical fiber connection component in which an optical waveguide of a planar lightwave circuit and an optical fiber can be connected after a process using SMT and reflow mounting technology. The optical fiber connection component includes: a plurality of fiber guide holes into which optical fibers are insertable at intervals equal to intervals of a plurality of optical waveguides of the planar lightwave circuit; and grooves for demarcating an area provided with the plurality of fiber guide holes and an area coated with an adhesive in an end surface to be joined with the planar lightwave circuit. The plurality of optical waveguides and the plurality of fiber guide holes are respectively aligned and fixed to the planar lightwave circuit with the adhesive in advance.

Abstract: An optical fiber guide part fixes optical fibers optically connected to optical waveguides of an optical waveguide device and is adhesively fixed to the optical waveguide device. The optical fiber guide part includes a V-grooved substrate, in a surface of which plural V-grooves are formed in parallel to one another, a lid member fixed to a top of the V-grooved substrate such that the V-grooves are exposed in a neighborhood of at least that end face of the V-grooved substrate which is on a side of the optical waveguide device, and a lid member fixed to an exposed part of the V-grooves of the V-grooved substrate, pressing, from above, the optical fibers inserted in guide holes formed by the V-grooves and the lid member placed on the V-grooves.

Abstract: An optical device includes a core formed on a substrate, a first source electrode and a second source electrode formed in contact with both side surfaces of the core interposed between the first source electrode and the second source electrode, and a drain electrode formed in contact with an upper surface of the core. The core, the first source electrode, and the second source electrode together form a plasmonic waveguide. The first source electrode and the second source electrode are Schottky coupled to the core.

Abstract: A core and a slab layer that are formed on a lower clad layer are provided. The lower clad layer is formed on a substrate. The core is comprised of a semiconductor and has a rectangular shape in a cross-sectional view. The slab layer is comprised of a semiconductor. The core and the slab layer have a thickness that allows only up to a secondary mode of light to be present. Further, the core and the slab layer are laminated on the lower clad layer. Further, the core and the slab layer are disposed to be optically coupled to each other.

Abstract: Optical alignment between an optical waveguide device and an optical connection part is realized easily and at low cost. An optical circuit in which optical waveguides to be connected to optical fibers are formed includes: an alignment optical waveguide configured to be opposed to, on an optical waveguide edge face to which an optical connection part having guide holes for insertion of core wires of the optical fibers is to be fixed, a guide hole into which an alignment optical fiber is to be inserted; and a light path changing member configured to change a path of light to a vertical direction with respect to the optical axis direction of the core of the alignment optical waveguide.

Abstract: There is provided an optical connection structure in which an optical fiber and an optical semiconductor waveguide are easily connected with low loss. The present invention relates to an optical connection structure configured to connect an optical waveguide device and an optical fiber including cores having different refractive indexes, wherein an optical connection component using a planar lightwave circuit is bonded and fixed on an end surface of an input/output waveguide of the optical waveguide device, a value of a refractive index of a core of the planar lightwave circuit is between a value of the refractive index of the core of the optical waveguide device and a value of the refractive index of the core of the optical fiber, and the optical waveguide device and the optical fiber are optically connected via the planar lightwave circuit.

Abstract: An optical module according to the present invention includes: a first plasmonic waveguide having one end formed of a first metal layer formed over an end portion of a first substrate, and having another end connected to one end of a first optical waveguide; a second metal layer that is formed on a side surface continuous with the end portion of the first substrate and formed to be continuous with the first metal layer; a second substrate provided with a second plasmonic waveguide formed of a third metal layer; and a second optical waveguide that is connected to the second plasmonic waveguide and formed on the second substrate, wherein the second metal layer and a part of the third metal layer are joined together to connect the first substrate to the second substrate.

Abstract: Provided is an optical fiber connection component in which an optical waveguide of a planar lightwave circuit and an optical fiber can be connected after a process using SMT and reflow mounting technology. The optical fiber connection component includes: a plurality of fiber guide holes into which optical fibers are insertable at intervals equal to intervals of a plurality of optical waveguides of the planar lightwave circuit; and grooves for demarcating an area provided with the plurality of fiber guide holes and an area coated with an adhesive in an end surface to be joined with the planar lightwave circuit. The plurality of optical waveguides and the plurality of fiber guide holes are respectively aligned and fixed to the planar lightwave circuit with the adhesive in advance.

Abstract: An optical module according to the present invention includes: a first plasmonic waveguide having one end formed of a first metal layer formed over an end portion of a first substrate, and having another end connected to one end of a first optical waveguide; a second metal layer that is formed on a side surface continuous with the end portion of the first substrate and formed to be continuous with the first metal layer; a second substrate provided with a second plasmonic waveguide formed of a third metal layer; and a second optical waveguide that is connected to the second plasmonic waveguide and formed on the second substrate, wherein the second metal layer and a part of the third metal layer are joined together to connect the first substrate to the second substrate.