Patents by Inventor Takehito Tanaka

Takehito Tanaka 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).

  • Patent number: 11003043
    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.
    Type: Grant
    Filed: February 24, 2020
    Date of Patent: May 11, 2021
    Assignee: TDK CORPORATION
    Inventors: Yasuhiro Ohmori, Masaharu Doi, Shintaro Takeuchi, Takehito Tanaka, Yoshinobu Kubota, Shinji Iwatsuka, Kenji Endou, Hiroki Hara, Toshinori Matsuura, Takashi Kikukawa
  • Patent number: 10989980
    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.
    Type: Grant
    Filed: February 24, 2020
    Date of Patent: April 27, 2021
    Assignees: TDK CORPORATION, FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Shinji Iwatsuka, Kenji Endou, Hiroki Hara, Toshinori Matsuura, Takashi Kikukawa, Yasuhiro Ohmori, Masaharu Doi, Shintaro Takeuchi, Takehito Tanaka, Yoshinobu Kubota
  • Publication number: 20200272020
    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.
    Type: Application
    Filed: February 24, 2020
    Publication date: August 27, 2020
    Inventors: Yasuhiro OHMORI, Masaharu DOI, Shintaro TAKEUCHI, Takehito TANAKA, Yoshinobu KUBOTA, Shinji IWATSUKA, Kenji ENDOU, Hiroki HARA, Toshinori MATSUURA, Takashi KIKUKAWA
  • Publication number: 20200271963
    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.
    Type: Application
    Filed: February 24, 2020
    Publication date: August 27, 2020
    Inventors: Shinji Iwatsuka, Kenji Endou, Hiroki Hara, Toshinori Matsuura, Takashi Kikukawa, Yasuhiro Ohmori, Masaharu Doi, Shintaro Takeuchi, Takehito Tanaka, Yoshinobu Kubota
  • Patent number: 10578885
    Abstract: A polarization coupling device includes a polarization combining element. The polarization combining element includes a polarization rotating unit that rotates a polarization direction of a first polarized wave incident on the polarization combining element, and a polarization combining unit that combines the first polarized wave with the polarization direction rotated by the polarization rotating unit and a second polarized wave incident on the polarization combining element with each other, and the polarization rotating unit and the polarization combining unit are integrated with each other. Due to this configuration, the polarization coupling device has an effect where downscaling of the device can be advanced.
    Type: Grant
    Filed: January 11, 2018
    Date of Patent: March 3, 2020
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Seimi Sasaki, Hiroshi Kato, Kohei Shibata, Takehito Tanaka
  • Patent number: 10031395
    Abstract: The present invention provides an optical modulator, which can be reduced in size with size reduction of an optical waveguide and electric wiring as compared to a conventional optical modulator. An optical modulator according to an embodiment includes a substrate; an optical waveguide provided on the substrate and configured to guide light; a modulation unit formed of part of the optical waveguide and configured to modulate the light; and electric wires provided on the substrate and configured to supply a high-frequency electric signal to the modulation unit. One end portion and another end portion of the optical waveguide are provided on a first end surface, one end portion of the electric wiring is provided along the first end surface, another end portion of the electric wiring is provided along a second end surface being different from the first end surface.
    Type: Grant
    Filed: January 26, 2017
    Date of Patent: July 24, 2018
    Assignees: FURUKAWA ELECTRIC CO., LTD., FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Yusuke Saito, Takehito Tanaka
  • Publication number: 20180196277
    Abstract: A polarization coupling device includes a polarization combining element. The polarization combining element includes a polarization rotating unit that rotates a polarization direction of a first polarized wave incident on the polarization combining element, and a polarization combining unit that combines the first polarized wave with the polarization direction rotated by the polarization rotating unit and a second polarized wave incident on the polarization combining element with each other, and the polarization rotating unit and the polarization combining unit are integrated with each other. Due to this configuration, the polarization coupling device has an effect where downscaling of the device can be advanced.
    Type: Application
    Filed: January 11, 2018
    Publication date: July 12, 2018
    Applicant: Fujitsu Optical Components Limited
    Inventors: Seimi SASAKI, Hiroshi KATO, Kohei SHIBATA, Takehito TANAKA
  • Patent number: 9954638
    Abstract: An optical module has an optical modulator configured to perform phase modulation on each of divided light components of an input light and output at least two phase-modulated signal lights, a semiconductor optical amplifier configured to amplify the phased-modulated signal lights in a same polarization mode, and a polarization multiplexer configured to convert the amplified signal lights into two orthogonally polarized signal lights and multiplex the orthogonally polarized signal lights.
    Type: Grant
    Filed: April 21, 2016
    Date of Patent: April 24, 2018
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Masaki Sugiyama, Takehito Tanaka
  • Patent number: 9864147
    Abstract: An optical modulator module includes: a semiconductor modulator that includes a plurality of output waveguides; a first cylindrical lens that has a longitudinal direction in a direction in which the plurality of output waveguides are aligned, and through which lights output from the plurality of output waveguides penetrate; and a plurality of second cylindrical lenses each having a longitudinal direction that intersects with the longitudinal direction of the first cylindrical lens and allowing a corresponding light of the lights output from the plurality of output waveguides to penetrate therethrough.
    Type: Grant
    Filed: March 30, 2016
    Date of Patent: January 9, 2018
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Hiroshi Kato, Shinji Maruyama, Kohei Shibata, Seimi Sasaki, Teruhiro Kubo, Takehito Tanaka
  • Publication number: 20170146886
    Abstract: The present invention provides an optical modulator, which can be reduced in size with size reduction of an optical waveguide and electric wiring as compared to a conventional optical modulator. An optical modulator according to an embodiment includes a substrate; an optical waveguide provided on the substrate and configured to guide light; a modulation unit formed of part of the optical waveguide and configured to modulate the light; and electric wires provided on the substrate and configured to supply a high-frequency electric signal to the modulation unit. One end portion and another end portion of the optical waveguide are provided on a first end surface, one end portion of the electric wiring is provided along the first end surface, another end portion of the electric wiring is provided along a second end surface being different from the first end surface.
    Type: Application
    Filed: January 26, 2017
    Publication date: May 25, 2017
    Applicants: FURUKAWA ELECTRIC CO., LTD., FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Yusuke SAITO, Takehito Tanaka
  • Patent number: 9638927
    Abstract: A polarization combiner includes: a base member that includes a body portion, an arm portion extending from the body portion, and a notch portion surrounded with the body portion and the arm portion; a polarization rotating element that is fixed to the arm portion of the base member and that rotates a polarization direction of a first polarized wave; and a polarization combining element that is fixed to the base member so as to face the notch portion of the base member and the polarization rotating element, the polarization combining element combining two polarized waves entering from a surface facing the notch portion and the polarization rotating element, the two polarized waves including the first polarized wave whose polarization direction is rotated by the polarization rotating element and a second polarized wave passing the notch portion.
    Type: Grant
    Filed: February 9, 2015
    Date of Patent: May 2, 2017
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Seimi Sasaki, Kohei Shibata, Teruhiro Kubo, Shinji Maruyama, Shintaro Takeuchi, Hiroshi Kato, Takehito Tanaka
  • Patent number: 9638861
    Abstract: A first lens transmits a beam of light having a vertical cross-sectional diameter made closer to a horizontal cross-sectional diameter. The beam of light is emitted from an optical waveguide on a substrate and configured such that the vertical cross-sectional diameter which is the diameter of a vertical cross section along the direction of the thickness of the substrate is greater than the horizontal cross-sectional diameter which is the diameter of a horizontal cross section along the direction of the width of the substrate. A second lens is disposed at a position, at which the vertical cross-sectional diameter and the horizontal cross-sectional diameter coincide with each other, so as to focus the beam of light on the optical fiber. The position is closer to the optical fiber than the first lens along the direction of travel of the beam of light transmitted by the first lens.
    Type: Grant
    Filed: February 25, 2015
    Date of Patent: May 2, 2017
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Shinji Maruyama, Seimi Sasaki, Kohei Shibata, Teruhiro Kubo, Shintaro Takeuchi, Hiroshi Kato, Takehito Tanaka
  • Publication number: 20170033884
    Abstract: An optical module has an optical modulator configured to perform phase modulation on each of divided light components of an input light and output at least two phase-modulated signal lights, a semiconductor optical amplifier configured to amplify the phased-modulated signal lights in a same polarization mode, and a polarization multiplexer configured to convert the amplified signal lights into two orthogonally polarized signal lights and multiplex the orthogonally polarized signal lights.
    Type: Application
    Filed: April 21, 2016
    Publication date: February 2, 2017
    Applicant: Fujitsu Optical Components Limited
    Inventors: Masaki SUGIYAMA, Takehito Tanaka
  • Publication number: 20160349457
    Abstract: An optical modulator module includes: a semiconductor modulator that includes a plurality of output waveguides; a first cylindrical lens that has a longitudinal direction in a direction in which the plurality of output waveguides are aligned, and through which lights output from the plurality of output waveguides penetrate; and a plurality of second cylindrical lenses each having a longitudinal direction that intersects with the longitudinal direction of the first cylindrical lens and allowing a corresponding light of the lights output from the plurality of output waveguides to penetrate therethrough.
    Type: Application
    Filed: March 30, 2016
    Publication date: December 1, 2016
    Applicant: Fujitsu Optical Components Limited
    Inventors: Hiroshi KATO, Shinji Maruyama, Kohei Shibata, Seimi Sasaki, Teruhiro Kubo, Takehito Tanaka
  • Patent number: 9461753
    Abstract: An optical receiver circuit includes a polarization beam splitter configured to split input signal light into two different polarized wave components; two variable optical attenuators configured to respectively adjust attenuation of and output the signal light split by the polarization beam splitter according to polarization state; and a single planar optical waveguide on which the polarization beam splitter and the two variable optical attenuators are disposed.
    Type: Grant
    Filed: January 28, 2015
    Date of Patent: October 4, 2016
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Shintaro Takeuchi, Takehito Tanaka
  • Patent number: 9448424
    Abstract: An optical module connected to an optical fiber for transmitting light includes: a substrate; a ferrule that is formed from a material capable of transmitting therethrough light having a predetermined wavelength, accommodates an end of the optical fiber, and is fixed on the substrate with a fixing agent cured by being irradiated with the light capable of passing through the material; and a semiconductor chip that is disposed on the substrate and modulates light emitted from the end of the optical fiber accommodated in the ferrule.
    Type: Grant
    Filed: February 24, 2015
    Date of Patent: September 20, 2016
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Kohei Shibata, Seimi Sasaki, Teruhiro Kubo, Shinji Maruyama, Shintaro Takeuchi, Hiroshi Kato, Takehito Tanaka
  • Patent number: 9405081
    Abstract: An optical transmitting apparatus includes: a substrate; optical modulators that are arranged in parallel to one another on the substrate and modulate light; waveguides that are formed on the substrate and guide signal light represented by at least one of modulated light beams obtained by the light being modulated by the plurality of optical modulators and monitor light represented by at least another one of the modulated light beams other than the signal light; lenses that collimate the signal light and the monitor light emitted from the waveguides; and a holding member that causes the signal light and the monitor light to be emitted from the lenses in mutually-different directions, by holding the lenses in such a manner that the optical axis of at least one of the lenses is out of alignment in a predetermined direction with the optical axis of at least one of the waveguides.
    Type: Grant
    Filed: February 24, 2015
    Date of Patent: August 2, 2016
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Shinji Maruyama, Seimi Sasaki, Kohei Shibata, Teruhiro Kubo, Shintaro Takeuchi, Hiroshi Kato, Takehito Tanaka
  • Patent number: 9229292
    Abstract: An optical module includes a waveguide substrate including an optical waveguide and electrodes that apply electronic signals to the optical waveguide; a relay substrate disposed adjacent to the waveguide substrate; a terminal substrate disposed adjacent to the waveguide substrate and opposite to the relay substrate across the waveguide substrate; and a carrier substrate on which the waveguide substrate, the relay substrate, and the terminal substrate are mounted. The electrodes have a first interconnect unit from the relay substrate to the terminal substrate via the waveguide substrate and second interconnect units from the first interconnect unit and branching on the terminal substrate. Among the second interconnect units, a first interconnect branch includes a capacitor and a terminal resistor; and a second interconnect branch is connected to an interconnect of the carrier substrate via a bias resistor, passes under the waveguide substrate to a DC electrode for bias-adjusting on the relay substrate.
    Type: Grant
    Filed: July 29, 2014
    Date of Patent: January 5, 2016
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Masaki Sugiyama, Seimi Sasaki, Takehito Tanaka
  • Patent number: 9231728
    Abstract: An optical module includes a waveguide substrate having an optical waveguide and electrodes that apply electronic signals to the optical waveguide; a relay substrate disposed adjacently to the waveguide substrate; and a termination substrate disposed sandwiching the waveguide substrate with the relay substrate. The electrodes respectively have a first wiring portion connected from the relay substrate through the waveguide substrate to the termination substrate and a second wiring portion extending from the first wiring portion and branching on the termination substrate. In the second wiring portion, one branched wiring portion has a capacitor and a termination resistor, and another branched wiring portion extends through a bias resistor to a DC electrode on the relay substrate. The second wiring portion is divided into a first group extending in a first direction along the optical waveguide and a second group extending in a direction opposite to the first direction.
    Type: Grant
    Filed: July 7, 2014
    Date of Patent: January 5, 2016
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Masaki Sugiyama, Seimi Sasaki, Takehito Tanaka
  • Publication number: 20150253506
    Abstract: A first lens transmits a beam of light having a vertical cross-sectional diameter made closer to a horizontal cross-sectional diameter. The beam of light is emitted from an optical waveguide on a substrate and configured such that the vertical cross-sectional diameter which is the diameter of a vertical cross section along the direction of the thickness of the substrate is greater than the horizontal cross-sectional diameter which is the diameter of a horizontal cross section along the direction of the width of the substrate. A second lens is disposed at a position, at which the vertical cross-sectional diameter and the horizontal cross-sectional diameter coincide with each other, so as to focus the beam of light on the optical fiber. The position is closer to the optical fiber than the first lens along the direction of travel of the beam of light transmitted by the first lens.
    Type: Application
    Filed: February 25, 2015
    Publication date: September 10, 2015
    Applicant: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Shinji MARUYAMA, Seimi Sasaki, Kohei Shibata, Teruhiro Kubo, Shintaro Takeuchi, Hiroshi Kato, Takehito Tanaka