Patents by Inventor Yoshinobu Kubota

Yoshinobu Kubota 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: 11693291
    Abstract: An optical waveguide device has a substrate, an intermediate layer, a thin-film LN layer containing an X-cut lithium niobate, and a buffer layer stacked on the substrate, and an optical waveguide having a ridge shape formed in the thin-film LN layer. The optical waveguide device includes a plurality of electrodes provided, respectively, at a first side and a second side of the optical waveguide. The electrodes are disposed so that respective bottom surfaces thereof are at positions lower than a position of a surface of the buffer layer.
    Type: Grant
    Filed: February 8, 2021
    Date of Patent: July 4, 2023
    Assignee: Fujitsu Optical Components Limited
    Inventors: Shuntaro Makino, Yoshinobu Kubota, Yasuhiro Ohmori, Masaharu Doi, Shintaro Takeuchi
  • Patent number: 11693290
    Abstract: An optical waveguide device includes a substrate on which an intermediate layer, a thin-film LN layer of lithium niobate, and a buffer layer are stacked; an optical waveguide formed in the thin-film LN layer; and a plurality of electrodes near the optical waveguide. The intermediate layer and the buffer layer contain a same material of a metal element of any one of group 3 of group 18 of a periodic table of elements.
    Type: Grant
    Filed: February 2, 2021
    Date of Patent: July 4, 2023
    Assignee: Fujitsu Optical Components Limited
    Inventors: Shuntaro Makino, Yoshinobu Kubota, Yasuhiro Ohmori, Masaharu Doi, Teruo Kurahashi, Shintaro Takeuchi
  • Publication number: 20230161184
    Abstract: An optical device includes a substrate, a first cladding layer that is laminated on one surface of the substrate, and a first optical waveguide that is formed in the first cladding layer at a side opposite to the substrate in the first cladding layer. The optical device further includes an electro-optic crystal layer that is laminated on a surface of the first cladding layer at a side opposite to the substrate, and a second optical waveguide that is formed of the electro-optic crystal layer on a surface of the electro-optic crystal layer at a side opposite to the first cladding layer. The optical device further includes a second cladding layer that is laminated on a surface of the electro-optic crystal layer at a side opposite to the first cladding layer.
    Type: Application
    Filed: September 19, 2022
    Publication date: May 25, 2023
    Applicant: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Shuntaro MAKINO, Teruo KURAHASHI, Yoshinobu KUBOTA, Yoshihiko YOSHIDA, Nobuaki MITAMURA, Takehito TANAKA
  • Patent number: 11624965
    Abstract: An optical waveguide device includes an intermediate layer, a thin-film LN layer including X-cut lithium niobate, and a buffer layer stacked on a substrate; an optical waveguide formed in the thin-film LN layer; and an electrode for driving. The intermediate layer is formed by an upper first intermediate layer and a lower second intermediate layer, the second intermediate layer having a permittivity that is smaller than a permittivity of the first intermediate layer.
    Type: Grant
    Filed: June 17, 2021
    Date of Patent: April 11, 2023
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Shuntaro Makino, Yoshinobu Kubota, Yasuhiro Ohmori, Masaharu Doi, Teruo Kurahashi
  • Publication number: 20230004028
    Abstract: An optical device includes a thin film Lithium Niobate (LN) layer, a first optical waveguide, and a second optical waveguide. The thin film LN layer is an X-cut or a Y-cut LN layer. The first optical waveguide is an optical waveguide that is formed on the thin film LN layer along a direction that is substantially perpendicular to a Z direction of a crystal axis of the thin film LN layer. The second optical waveguide is an optical waveguide that is routed and connected to the first optical waveguide. At least a part of a core of the first optical waveguide is made thicker than a core of the second optical waveguide.
    Type: Application
    Filed: April 21, 2022
    Publication date: January 5, 2023
    Applicant: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Shuntaro MAKINO, Yoshinobu KUBOTA, Yasuhiro OHMORI, Masaharu DOI, Masaki SUGIYAMA, Shintaro TAKEUCHI, Yoshihiko YOSHIDA, Shinji MARUYAMA, Teruo KURAHASHI
  • Publication number: 20220373828
    Abstract: An optical device includes a silicon substrate, a waveguide formed of a thin film that is laminated on the silicon substrate and that is made of a perovskite oxide with a large electro-optic effect as compared to lithium niobate, and a cladding layer that covers the waveguide. Further, the optical device includes ground electrode that has a ground potential and a signal electrode that is arranged at a position facing the ground electrode and that applies driving voltage to the waveguide.
    Type: Application
    Filed: March 21, 2022
    Publication date: November 24, 2022
    Applicant: Fujitsu Optical Components Limited
    Inventors: YOSHIHIKO YOSHIDA, NOBUAKI MITAMURA, Shuntaro Makino, Yoshinobu Kubota
  • Publication number: 20220050351
    Abstract: An optical waveguide device includes an intermediate layer, a thin-film LN layer including X-cut lithium niobate, and a buffer layer stacked on a substrate; an optical waveguide formed in the thin-film LN layer; and an electrode for driving. The intermediate layer is formed by an upper first intermediate layer and a lower second intermediate layer, the second intermediate layer having a permittivity that is smaller than a permittivity of the first intermediate layer.
    Type: Application
    Filed: June 17, 2021
    Publication date: February 17, 2022
    Applicant: Fujitsu Optical Components Limited
    Inventors: Shuntaro Makino, Yoshinobu Kubota, Yasuhiro Ohmori, Masaharu Doi, Teruo Kurahashi
  • Publication number: 20210373416
    Abstract: An optical modulator in which an optical signal is input from one side of a package, includes in the package, a chip that optically modulates the optical signal and in which an input waveguide and an output waveguide of the optical signal are led to mutually different destinations each being one end of the chip facing the one side of the package and a side surface of the chip orthogonal to the one end of the chip; an input optical system coupled to the input waveguide of the chip; and an output optical system coupled to the output waveguide of the chip.
    Type: Application
    Filed: February 5, 2021
    Publication date: December 2, 2021
    Applicant: Fujitsu Optical Components Limited
    Inventors: Shinji Maruyama, Shuntaro Makino, Yoshimitsu SAKAI, Yoshinobu Kubota
  • Publication number: 20210325761
    Abstract: An optical waveguide device has a substrate, an intermediate layer, a thin-film LN layer containing an X-cut lithium niobate, and a buffer layer stacked on the substrate, and an optical waveguide having a ridge shape formed in the thin-film LN layer. The optical waveguide device includes a plurality of electrodes provided, respectively, at a first side and a second side of the optical waveguide. The electrodes are disposed so that respective bottom surfaces thereof are at positions lower than a position of a surface of the buffer layer.
    Type: Application
    Filed: February 8, 2021
    Publication date: October 21, 2021
    Applicant: Fujitsu Optical Components Limited
    Inventors: Shuntaro MAKINO, Yoshinobu KUBOTA, Yasuhiro OHMORI, Masaharu DOI, Shintaro TAKEUCHI
  • Publication number: 20210325760
    Abstract: An optical waveguide device includes a substrate on which an intermediate layer, a thin-film LN layer of lithium niobate, and a buffer layer are stacked; an optical waveguide formed in the thin-film LN layer; and a plurality of electrodes near the optical waveguide. The intermediate layer and the buffer layer contain a same material of a metal element of any one of group 3 of group 18 of a periodic table of elements.
    Type: Application
    Filed: February 2, 2021
    Publication date: October 21, 2021
    Applicant: Fujitsu Optical Components Limited
    Inventors: Shuntaro Makino, Yoshinobu Kubota, Yasuhiro Ohmori, Masaharu Doi, Teruo Kurahashi, Shintaro Takeuchi
  • Patent number: 11086149
    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: Grant
    Filed: March 27, 2020
    Date of Patent: August 10, 2021
    Assignees: TDK CORPORATION, FUJITSU OPTICAL COMPONENTS LIMITED
    Inventors: Shinji Iwatsuka, Kenji Sasaki, Hiroki Hara, Yasuhiro Ohmori, Masaharu Doi, Shintaro Takeuchi, Yoshihiko Yoshida, 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: 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: 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: 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
  • 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
  • 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