Patents by Inventor Masaharu Doi

Masaharu Doi 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: 11003044
    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.
    Type: Grant
    Filed: February 24, 2020
    Date of Patent: May 11, 2021
    Assignees: TDK CORPORATION, FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Hiroki Hara, Shinji Iwatsuka, Takashi Kikukawa, Toshinori Matsuura, Yasuhiro Ohmori, Masaharu Doi, Shintaro Takeuchi, Yoshinobu Kubota
  • 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: 20210103165
    Abstract: An electro-optic device is provided with a substrate, an optical waveguide formed of a lithium niobate film with a ridge shape on the substrate, and an electrode that applies an electric field to the optical waveguide. The optical waveguide includes a modulation waveguide provided in an electric field application region applied with the electric field and having a thickness of 1 ?m or larger and a bent waveguide provided in a region other than the electric field application region and having a curvature radius of 16 ?m or larger and 80 ?m or smaller.
    Type: Application
    Filed: March 27, 2020
    Publication date: April 8, 2021
    Inventors: Shinji IWATSUKA, Kenji SASAKI, Hiroki HARA, Yasuhiro OHMORI, Masaharu DOI, Shintaro TAKEUCHI, Yoshihiko YOSHIDA, Yoshinobu KUBOTA
  • Publication number: 20200310216
    Abstract: An electro-optic device is provided with a substrate, an optical waveguide formed of a lithium niobate film with a ridge shape on the substrate, and an electrode that applies an electric field to the optical waveguide. The optical waveguide includes a first waveguide section provided at least in an electric field application region applied with the electric field and having a thickness of 1 ?m or larger and a second waveguide section provided in a region other than the electric field application region and having a thickness of 0.3 ?m or larger and less than 1 ?m.
    Type: Application
    Filed: March 27, 2020
    Publication date: October 1, 2020
    Inventors: Shinji IWATSUKA, Kenji SASAKI, Hiroki HARA, Yasuhiro OHMORI, Masaharu DOI, Shintaro TAKEUCHI, Yoshihiko YOSHIDA, Yoshinobu KUBOTA
  • Publication number: 20200298882
    Abstract: According to one embodiment, a transport service method comprises organizing a vehicle group of a plurality of self-driving vehicles in which a parameter value inherent to vehicles falls within a predetermined range, and controlling cooperative travel of the self-driving vehicles in the vehicle group to perform transport service of baggage, persons, animals, and the like.
    Type: Application
    Filed: June 5, 2020
    Publication date: September 24, 2020
    Applicant: TOSHIBA DIGITAL SOLUTIONS CORPORATION
    Inventors: Megumi KOBAYASHI, Yasuto HATAFUKU, Masahiro SAMEJIMA, Hideki KUBO, Motokazu IWASAKI, Yoko IKEDA, Shinsuke IUCHI, Kiyoshi TAKEMOTO, Keishi HIGASHI, Kaori KITAMI, Masaharu DOI, Tatsuki SHIRAISHI, Keiji OGATA, Yoshiki YAMAOKA, Masaru WATABIKI, Takeshi NAGAI, Masao UOZUMI, Masatomo SAITO, Michiyo SATO, Masanori TAKAHASHI
  • Publication number: 20200272021
    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.
    Type: Application
    Filed: February 24, 2020
    Publication date: August 27, 2020
    Applicant: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Hiroki HARA, Shinji IWATSUKA, Takashi KIKUKAWA, Toshinori MATSUURA, Yasuhiro OHMORI, Masaharu DOI, Shintaro TAKEUCHI, 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: 10754179
    Abstract: An optical modulator includes an optical waveguide of a ridge type formed of a thin film of a dielectric material having an electro-optic effect over a substrate, a buffer layer covering the optical waveguide, and a signal electrode provided over the optical waveguide via the buffer layer, wherein a width of the signal electrode is greater than a ridge width of the optical waveguide and wherein the signal electrode covers at least one of sidewalls of a ridge of the optical waveguide.
    Type: Grant
    Filed: July 18, 2019
    Date of Patent: August 25, 2020
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Yasuhiro Ohmori, Yoshinobu Kubota, Masaharu Doi, Shintaro Takeuchi, Yoshihiko Yoshida
  • Publication number: 20200041824
    Abstract: An optical modulator includes an optical waveguide of a ridge type formed of a thin film of a dielectric material having an electro-optic effect over a substrate, a buffer layer covering the optical waveguide, and a signal electrode provided over the optical waveguide via the buffer layer, wherein a width of the signal electrode is greater than a ridge width of the optical waveguide and wherein the signal electrode covers at least one of sidewalls of a ridge of the optical waveguide.
    Type: Application
    Filed: July 18, 2019
    Publication date: February 6, 2020
    Applicant: Fujitsu Optical Components Limited
    Inventors: Yasuhiro OHMORI, Yoshinobu KUBOTA, Masaharu DOI, Shintaro TAKEUCHI, Yoshihiko YOSHIDA
  • Patent number: 10303036
    Abstract: An optical modulator includes a substrate and an optical waveguide group. The optical waveguide group includes a pair of relay optical waveguides, a pair of first Mach-Zehnder type optical waveguides, and a pair of second Mach-Zehnder type optical waveguides. The pair of the first Mach-Zehnder type optical waveguides are connected to the pair of the relay optical waveguides and includes input ends arranged at positions that deviate from each other in a longitudinal direction of the substrate. The pair of the second Mach-Zehnder type optical waveguides are provided on a pair of branched waveguides of each of the first Mach-Zehnder type optical waveguides and includes input ends arranged at symmetric positions with respect to a straight line that passes through an input end serving as a branch point of the branched waveguides and that extends in the longitudinal direction of the substrate.
    Type: Grant
    Filed: July 12, 2017
    Date of Patent: May 28, 2019
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Shintaro Takeuchi, Yoshihiko Yoshida, Yoshinobu Kubota, Masaharu Doi, Yasuhiro Ohmori
  • Patent number: 10295883
    Abstract: An optical module includes a driver that is provided on a board and generates an electrical signal according to a data signal, and an optical modulator that is connected to an optical fiber and provided on the board and that modulates light emitted from the optical fiber using the electrical signal generated by the driver. The optical module has a cut-out portion that is formed by cutting out part of its outer shape and that accommodates the driver so that the driver overlaps the optical fiber when viewed from a direction perpendicular to the board.
    Type: Grant
    Filed: July 13, 2017
    Date of Patent: May 21, 2019
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Shinji Maruyama, Masaharu Doi
  • Patent number: 10268099
    Abstract: An optical modulator connected to a first optical fiber and a second optical fiber arranged in parallel includes an optical-path changing unit that redirects light emerging from a tip of the first optical fiber toward a tip of the second optical fiber and an optical modulation chip that modulates the light redirected by the optical-path changing unit and outputs a light beam obtained by modulating the light to a tip of the second optical fiber.
    Type: Grant
    Filed: August 17, 2017
    Date of Patent: April 23, 2019
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Masaharu Doi, Shinji Maruyama, Yoshinobu Kubota
  • Patent number: 10175553
    Abstract: An optical module includes a driver that generates an electric signal and an optical modulator that has a notch in which at least a portion of the driver is accommodated and performs optical modulation using an electric signal generated by the driver. The optical module also includes a first connector electrically connected to the driver in the notch of the optical modulator. The optical module further includes a second connector provided on a surface of the notch of the optical modulator, the surface being opposed to the first connector. The second connector is electrically connected to the optical modulator. Furthermore, the optical module includes a coaxial pin that is connected to the first connector and the second connector and transmits the electric signal generated by the driver to the optical modulator.
    Type: Grant
    Filed: December 20, 2016
    Date of Patent: January 8, 2019
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Akira Ishii, Shinji Maruyama, Yuki Sakurai, Masaharu Doi, Osamu Oyama, Masami Kamioka
  • Patent number: 10095080
    Abstract: An optical modulator includes an optical modulator chip configured to optically modulate an optical signal using an electrical signal input thereto; and a relay substrate configured to relay and couple the electrical signal to the optical modulator chip. The optical modulator chip includes a signal electrode and a ground electrode for the electrical signal, formed along a waveguide for the optical signal. One end of the optical modulator chip is arranged to face the relay substrate. An electrode connection portion coupling the electrical signal to the relay substrate by wire is provided at the one end. A distance between a tip of one end of the signal electrode in the electrode connection portion and the end of the optical modulator chip is less than a distance between a tip of an end of the ground electrode in the electrode connection portion and the end of the optical modulator chip.
    Type: Grant
    Filed: July 14, 2017
    Date of Patent: October 9, 2018
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Yasuhiro Ohmori, Yoshinobu Kubota, Masaharu Doi, Masaki Sugiyama
  • Patent number: 10082683
    Abstract: An optical modulator includes: a ferroelectric substrate in which an input optical waveguide, a pair of branched optical waveguides, and an output optical waveguide are formed; a signal electrode that is formed in a vicinity of at least one of the pair of branched optical waveguides; a first protection member that is attached to an input end of the ferroelectric substrate in which the input optical waveguide is formed; and a second protection member that is attached to an output end of the ferroelectric substrate in which the output optical waveguide is formed. The first protection member and the second protection member have a Mohs hardness that is less than or equal to a Mohs hardness of the ferroelectric substrate, and are formed of a glass material that does not have a pyroelectric effect.
    Type: Grant
    Filed: June 8, 2017
    Date of Patent: September 25, 2018
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Yoshihiko Yoshida, Masaharu Doi, Yoshinobu Kubota
  • Patent number: 10054744
    Abstract: An optical module includes a substrate on which an optical waveguide is formed, and an optical fiber assembly. The optical fiber assembly includes an optical fiber, a translucent member, and a mirror portion. The translucent member includes a joint surface joined to an end surface of the substrate at an end of the optical waveguide, and is attached to a distal end of the optical fiber. The mirror portion is formed on the translucent member, reflects light emitted from the distal end of the optical fiber in a direction different from a traveling direction of the light, and collects the reflected light into the end of the optical waveguide through the joint surface.
    Type: Grant
    Filed: March 11, 2016
    Date of Patent: August 21, 2018
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Masaharu Doi, Akira Ishii, Teruhiro Kubo, Yoshinobu Kubota
  • Publication number: 20180120670
    Abstract: An optical modulator connected to a first optical fiber and a second optical fiber arranged in parallel includes an optical-path changing unit that redirects light emerging from a tip of the first optical fiber toward a tip of the second optical fiber and an optical modulation chip that modulates the light redirected by the optical-path changing unit and outputs a light beam obtained by modulating the light to a tip of the second optical fiber.
    Type: Application
    Filed: August 17, 2017
    Publication date: May 3, 2018
    Applicant: Fujitsu Optical Components Limited
    Inventors: Masaharu DOI, Shinji MARUYAMA, Yoshinobu KUBOTA
  • Publication number: 20180095339
    Abstract: An optical module includes a driver that is provided on a board and generates an electrical signal according to a data signal, and an optical modulator that is connected to an optical fiber and provided on the board and that modulates light emitted from the optical fiber using the electrical signal generated by the driver. The optical module has a cut-out portion that is formed by cutting out part of its outer shape and that accommodates the driver so that the driver overlaps the optical fiber when viewed from a direction perpendicular to the board.
    Type: Application
    Filed: July 13, 2017
    Publication date: April 5, 2018
    Applicant: Fujitsu Optical Components Limited
    Inventors: Shinji MARUYAMA, Masaharu Doi