Patents by Inventor Ryoichi Kasahara
Ryoichi Kasahara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20220019125Abstract: With a wavelength conversion device based on a nonlinear optical effect, when arrayed waveguides including an intended nonlinear waveguide are fabricated, unwanted slab waveguides are inevitably formed. The slab waveguides can cause an erroneous measurement in the selection of a waveguide having desired characteristics from the arrayed waveguides. The erroneous measurement can lead to redoing steps for fabricating the wavelength conversion device and a decrease in the yield and inhibit the evaluation of the characteristics in selection of the waveguide and the subsequent fabrication of the wavelength conversion device from being efficiently performed. A wavelength conversion device according to the present invention includes a plurality of waveguides formed on a substrate, and a plurality of slab waveguides that are arranged substantially in parallel with and spaced apart from the plurality of waveguides, and each of the slab waveguides has a grating structure that reflects light of a particular wavelength.Type: ApplicationFiled: November 13, 2019Publication date: January 20, 2022Inventors: Takushi Kazama, Takahiro Kashiwazaki, Osamu Tadanaga, Koji Embutsu, Ryoichi Kasahara, Takeshi Umeki
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Publication number: 20220011647Abstract: A wavelength conversion element manufacturing method capable of realizing, in a wavelength conversion element having a structure in which a thin film substrate having a periodic polarization inversion structure and a support substrate are laminated, highly efficient wavelength conversion by confining light in a cross-sectional area smaller than in the known art.Type: ApplicationFiled: October 8, 2019Publication date: January 13, 2022Inventors: Takahiro Kashiwazaki, Takeshi Umeki, Ryoichi Kasahara, Osamu Tadanaga, Koji Embutsu, Takushi Kazama
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Publication number: 20220004081Abstract: Reduction of output power of light with a wavelength converted is suppressed, which is caused by a pyroelectric effect that occurs when a temperature of a wavelength conversion element including a ferroelectric substrate is changed. Provided is a wavelength conversion device that generates light different from a wavelength of a signal light when the signal light is inputted, and includes a wavelength conversion element that converts a wavelength of the signal light, and a temperature control element for controlling a temperature of the wavelength conversion element, wherein the wavelength conversion element and the temperature control element are sealed in an inside of a metal casing, the wavelength conversion element includes an optical waveguide core and a substrate having a lower refractive index to the signal light than the optical waveguide core, and the substrate is a ferroelectric substance in which directions of spontaneous polarization are random.Type: ApplicationFiled: November 12, 2019Publication date: January 6, 2022Inventors: Koji Embutsu, Ryoichi Kasahara, Osamu Tadanaga, Takeshi Umeki, Takahiro Kashiwazaki, Takushi Kazama
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Publication number: 20210405502Abstract: A wavelength conversion apparatus using a nonlinear optical medium having a periodically poled structure is operated at an optimal temperature in a stable manner. The wavelength conversion apparatus includes a wavelength converter using a nonlinear optical medium and a controller for controlling temperature of the wavelength converter. The wavelength conversion apparatus further includes a first optical branch coupler for branching part of output light from the wavelength converter, and first and second wavelength separation filters for separating and outputting, from part of the output light, each of two light components generated by parametric fluorescence in the wavelength converter. The controller controls the temperature of the wavelength converter on the basis of difference in light intensity of the two light components.Type: ApplicationFiled: October 29, 2019Publication date: December 30, 2021Inventors: Takeshi Umeki, Takushi Kazama, Koji Embutsu, Takahiro Kashiwazaki, Osamu Tadanaga, Ryoichi Kasahara
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Publication number: 20210302153Abstract: Provided is a fringe projection device capable of adjusting resolution and measurement accuracy without increasing the number of light sources, performing position adjustment of the emission point and the surface to be inspected, or increasing device costs and measurement procedures. A waveguide-type optical phase modulator of the present invention includes a waveguide-type optical element in which an optical waveguide is formed on a substrate, the waveguide-type optical element including: at least one input waveguide to which an optical signal is input; a one-input and N-output (N is an integer of 2 or more) branch waveguide that is optically connected to an output of the input waveguide; 1×M (M is an integer of 2 or more) optical switches that are optically connected to outputs of the branch waveguide; (N×M) phase shifters that are optically connected to outputs of the optical switches; and (N×M) output waveguides that are optically connected to outputs of the phase shifters.Type: ApplicationFiled: August 1, 2019Publication date: September 30, 2021Inventors: Satomi Katayose, Ryoichi Kasahara, Yuji Fujiwara
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Publication number: 20210263219Abstract: To provide a planar lightwave circuit capable of being optically connected to a semiconductor optical element or an optical wiring component in a simple, precise, and stable manner without an increase in circuit footprint or the number of fabrication steps or a deterioration of characteristics. By arranging a dummy optical waveguide having a mirror function in the vicinity of an input/output waveguide of an optical functional circuit forming the planar lightwave circuit, a semiconductor optical element or an optical wiring component can be easily aligned with and fixed to the optical functional circuit by monitoring the reflection light intensity from the dummy optical waveguide. When the optical functional circuit has a plurality of input/output waveguides to be optically connected, each input/output waveguide can be identified if the dummy optical waveguides having the mirror function have different reflection properties (such as reflectance, width, position, or reflection wavelength).Type: ApplicationFiled: May 23, 2019Publication date: August 26, 2021Inventors: Yuji Fujiwara, Satomi Katayose, Ryoichi Kasahara, Takahiro Kashiwazaki, Junji Sakamoto
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Publication number: 20210255395Abstract: Provided is an optical waveguide circuit in which the space between waveguides, a waveguide groove, or the space between fibers is filled with a resin where a wavelength shifts to positive (shifts backward) instead of a conventional resin where a wavelength shifts to negative (shifts forward), to return a refractive index having decreased by an instantaneous change to the original refractive index. In the filling resin with which the space between the waveguides, the waveguide groove, the space between the fibers, or the space between the fiber and the waveguide is filled, upon input of light, a refractive index of a portion through which the light passes instantaneously decreases, and then the refractive index gradually increases to compensate the initial decrease in the refractive index.Type: ApplicationFiled: May 23, 2019Publication date: August 19, 2021Inventors: Katsuhiko Hirabayashi, Nobutatsu Koshobu, Ryoichi Kasahara
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Publication number: 20210240015Abstract: A method for adjusting a transmission wavelength of signal light transmitted through an optical waveguide device provided with one or more optical waveguides through which the signal light having a wavelength of 1520 nm to 1560 nm and blue light having a wavelength of 375 nm to 455 nm pass, a groove through which the waveguide passes, and resin filled in the groove, including a step of passing the signal light and the blue light through the same or mutually different one or more optical waveguides and of passing the signal light and the blue light through the same or mutually different resin, the latter step changing a refractive index of the resin by irradiating the resin with the blue light so as to change the transmission wavelength of the signal light transmitted through the resin in accordance with a change in the refractive index of the resin.Type: ApplicationFiled: July 26, 2019Publication date: August 5, 2021Inventors: Katsuhiko Hirabayashi, Nobutatsu Koshobu, Satomi Katayose, Ryoichi Kasahara
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Patent number: 11076793Abstract: There is provided a respiration estimation apparatus.Type: GrantFiled: November 4, 2016Date of Patent: August 3, 2021Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Takayuki Ogasawara, Takuro Tajima, Kei Kuwabara, Nobuaki Matsuura, Ryoichi Kasahara
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Publication number: 20210223471Abstract: With a wavelength conversion device based on a nonlinear optical effect, when arrayed waveguides including an intended nonlinear waveguide are fabricated, unwanted slab waveguides are inevitably formed. The slab waveguides can cause an erroneous measurement in the selection of a waveguide having desired characteristics from the arrayed waveguides. The erroneous measurement can lead to redoing steps for fabricating the wavelength conversion device and a decrease in the yield and inhibit the evaluation of the characteristics in selection of the waveguide and the subsequent fabrication of the wavelength conversion device from being efficiently performed. A wavelength conversion device according to the present invention includes a plurality of waveguides formed on a substrate, and a plurality of slab waveguides that are arranged substantially in parallel with and spaced apart from the plurality of waveguides, and a guided light attenuator is formed in each of the slab waveguides.Type: ApplicationFiled: April 18, 2019Publication date: July 22, 2021Inventors: Takahiro Kashiwazaki, Ryoichi Kasahara, Osamu Tadanaga, Takeshi Umeki, Koji Embutsu, Takushi Kazama
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Patent number: 11002995Abstract: A fringe projector apparatus includes: a phase modulator having a first waveguide, a second waveguide, and a plurality of heaters including a first heater and a second heater, wherein the first and second waveguides and the plurality of heaters are provided on a single substrate, and wherein the first heater heats the first waveguide and the second heater heats a position away from the first waveguide; a light source that generates a light beam to be input to the first waveguide and the second waveguide; and a controller that controls a phase difference between the first waveguide and the second waveguide by changing an electric power consumption of the first heater under a condition that a total electric power consumption of the plurality of heaters is constant.Type: GrantFiled: July 16, 2019Date of Patent: May 11, 2021Assignees: OLYMPUS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Daichi Watanabe, Satomi Katayose, Kei Watanabe, Yu Kurata, Ryoichi Kasahara
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Patent number: 10969281Abstract: An illumination apparatus generates an interference fringe. An input arm receives an input light beam from a light source. A splitter splits the input light beam that has passed through the input arm into a first output arm and a second output arm. A phase modulator changes a phase difference between the output light beams of the first output arm and the second output arm. A phase detector detects the phase difference between output light beams respectively output from the first output arm and the second output arm based on a return light beam generated by combining a first reflected light beam and a second reflected light beam respectively reflected by ends of the first output arm and the second output arm.Type: GrantFiled: July 22, 2019Date of Patent: April 6, 2021Assignees: OLYMPUS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Daichi Watanabe, Kei Watanabe, Yu Kurata, Satomi Katayose, Ryoichi Kasahara
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Publication number: 20210044358Abstract: The present invention provides a configuration of a novel optical transmitter which outputs stable PDM signals. The novel optical transmitter generates phase conjugate light using a single second-order non-linear optical element included in a phase conjugate light generator with a looped configuration. A relative phase of main signal light with respect to excitation light and phase conjugate light of the main signal light stabilizes between two polarized components, and a PDM signal including a pair of a polarization-multiplexed signal and phase conjugate light in a stable phase state can be generated and transmitted. The present invention can provide an optical transmitter that generates a PDM signal in which a variation in a phase between quadrature polarized waves is suppressed. By stabilizing quality of a PDM transmission signal on a side of the optical transmitter, a phase sensitive amplifier in a polarization diversity configuration can be operated in a stable manner.Type: ApplicationFiled: March 7, 2019Publication date: February 11, 2021Inventors: Takushi Kazama, Takeshi Umeki, Takahiro Kashiwazaki, Koji Embutsu, Osamu Tadanaga, Ryoichi Kasahara
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Publication number: 20200386943Abstract: A dependency of a characteristic of an optical circuit on an optical signal intensity occurring due to input of a high intensity optical signal is reduced in a waveguide type optical interferometer circuit. The waveguide type optical interferometer circuit is a waveguide type optical interferometer circuit formed in one plane, and includes an input waveguide, an optical branching unit, an optical coupling unit, an output waveguide, and optical waveguides having different lengths from each other and being interposed between the optical branching unit and the optical coupling unit. A light intensity compensating region is formed on an optical path extending from the optical branching unit to the optical coupling unit, and the light intensity compensating region is formed by using a light intensity compensating material having a light intensity coefficient different from a light intensity coefficient of an optical distance relative to an incident light intensity in the optical path.Type: ApplicationFiled: February 21, 2019Publication date: December 10, 2020Inventors: Nobutatsu Koshoubu, Ryoichi Kasahara, Katsuhiko Hirabayashi
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Publication number: 20200363694Abstract: A problem is to provide a planar lightwave circuit optical device capable of facilitating mounting of connection to a printed circuit board and realizing downsizing of a device chip. A planar lightwave circuit optical device of the present invention is characterized by mounting an electrical connector (FPC connector) by means of soldering on an electrode pad of an electrical wire connected to an electrical drive unit (such as a heater) in a device formed by using a planar lightwave circuit (PLC).Type: ApplicationFiled: November 30, 2018Publication date: November 19, 2020Inventors: Ai Yanagihara, Kenya Suzuki, Ryoichi Kasahara, Kazunori Seno, Yuko Kawajiri
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Patent number: 10799136Abstract: A bioelectrode includes a fitting member (1106) formed by an electrically insulating member fixed on a surface of a garment (1100) that comes in contact with a living body (1000), an electrode part (1101a) formed by a conductive member fixed on a surface of the fitting member (1106) that comes in contact with the living body (1000), a connector (1102a) fixed to the fitting member (1106) and configured to connect a bioelectric signal measurement device, a wiring line (1103a) fixed to the fitting member (1106) and configured to electrically connect the connector (1102a) and the electrode part (1101a), and an electrically-insulating insulating member (1105) configured to cover a portion within the surface of the wiring line (1103a) that comes in contact with the living body (1000).Type: GrantFiled: December 7, 2015Date of Patent: October 13, 2020Assignees: NIPPON TELEGRAPH AND TELEPHONE CORPORATION, TORAY INDUSTRIES, INC.Inventors: Kazuhiko Takagahara, Ryusuke Kawano, Takako Ishihara, Michiko Seyama, Ryoichi Kasahara, Yasuhiro Sato, Atsushi Horiuchi, Masanobu Sato, Emiko Ishikawa, Keiji Takeda, Noriko Nagai
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Publication number: 20190339055Abstract: An illumination apparatus generates an interference fringe. An input arm receives an input light beam from a light source. A splitter splits the input light beam that has passed through the input arm into a first output arm and a second output arm. A phase modulator changes a phase difference between the output light beams of the first output arm and the second output arm. A phase detector detects the phase difference between output light beams respectively output from the first output arm and the second output arm based on a return light beam generated by combining a first reflected light beam and a second reflected light beam respectively reflected by ends of the first output arm and the second output arm.Type: ApplicationFiled: July 22, 2019Publication date: November 7, 2019Applicants: OLYMPUS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Daichi WATANABE, Kei WATANABE, Yu KURATA, Satomi KATAYOSE, Ryoichi KASAHARA
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Publication number: 20190339069Abstract: An optical measurement apparatus includes a light projector that projects a patterned light, and an imager that captures an image of a target onto which the patterned light has been projected. The light projector and the imager are fixed to each other via a mounting face that intersects both a projection axis direction of the light projector and an image acquisition axis direction of the imager.Type: ApplicationFiled: July 22, 2019Publication date: November 7, 2019Applicants: OLYMPUS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Daichi WATANABE, Kanto MIYAZAKI, Satomi KATAYOSE, Kei WATANABE, Yu KURATA, Ryoichi KASAHARA
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Publication number: 20190339549Abstract: A fringe projector apparatus includes: a phase modulator having a first waveguide, a second waveguide, and a plurality of heaters including a first heater and a second heater, wherein the first and second waveguides and the plurality of heaters are provided on a single substrate, and wherein the first heater heats the first waveguide and the second heater heats a position away from the first waveguide; a light source that generates a light beam to be input to the first waveguide and the second waveguide; and a controller that controls a phase difference between the first waveguide and the second waveguide by changing an electric power consumption of the first heater under a condition that a total electric power consumption of the plurality of heaters is constant.Type: ApplicationFiled: July 16, 2019Publication date: November 7, 2019Applicants: OLYMPUS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Daichi WATANABE, Satomi KATAYOSE, Kei WATANABE, Yu KURATA, Ryoichi KASAHARA
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Publication number: 20190320926Abstract: There is provided a heartbeat detection device.Type: ApplicationFiled: September 25, 2017Publication date: October 24, 2019Inventors: Nobuaki MATSUURA, Kei KUWABARA, Takayuki OGASAWARA, Ryoichi KASAHARA, Koji FUJII