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: 11693291Abstract: 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: GrantFiled: February 8, 2021Date of Patent: July 4, 2023Assignee: Fujitsu Optical Components LimitedInventors: Shuntaro Makino, Yoshinobu Kubota, Yasuhiro Ohmori, Masaharu Doi, Shintaro Takeuchi
-
Patent number: 11693290Abstract: 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: GrantFiled: February 2, 2021Date of Patent: July 4, 2023Assignee: Fujitsu Optical Components LimitedInventors: Shuntaro Makino, Yoshinobu Kubota, Yasuhiro Ohmori, Masaharu Doi, Teruo Kurahashi, Shintaro Takeuchi
-
Publication number: 20230161184Abstract: 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: ApplicationFiled: September 19, 2022Publication date: May 25, 2023Applicant: FUJITSU OPTICAL COMPONENTS LIMITEDInventors: Shuntaro MAKINO, Teruo KURAHASHI, Yoshinobu KUBOTA, Yoshihiko YOSHIDA, Nobuaki MITAMURA, Takehito TANAKA
-
Patent number: 11624965Abstract: 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: GrantFiled: June 17, 2021Date of Patent: April 11, 2023Assignee: FUJITSU OPTICAL COMPONENTS LIMITEDInventors: Shuntaro Makino, Yoshinobu Kubota, Yasuhiro Ohmori, Masaharu Doi, Teruo Kurahashi
-
Publication number: 20230004028Abstract: 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: ApplicationFiled: April 21, 2022Publication date: January 5, 2023Applicant: FUJITSU OPTICAL COMPONENTS LIMITEDInventors: Shuntaro MAKINO, Yoshinobu KUBOTA, Yasuhiro OHMORI, Masaharu DOI, Masaki SUGIYAMA, Shintaro TAKEUCHI, Yoshihiko YOSHIDA, Shinji MARUYAMA, Teruo KURAHASHI
-
Publication number: 20220373828Abstract: 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: ApplicationFiled: March 21, 2022Publication date: November 24, 2022Applicant: Fujitsu Optical Components LimitedInventors: YOSHIHIKO YOSHIDA, NOBUAKI MITAMURA, Shuntaro Makino, Yoshinobu Kubota
-
Publication number: 20220050351Abstract: 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: ApplicationFiled: June 17, 2021Publication date: February 17, 2022Applicant: Fujitsu Optical Components LimitedInventors: Shuntaro Makino, Yoshinobu Kubota, Yasuhiro Ohmori, Masaharu Doi, Teruo Kurahashi
-
Publication number: 20210373416Abstract: 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: ApplicationFiled: February 5, 2021Publication date: December 2, 2021Applicant: Fujitsu Optical Components LimitedInventors: Shinji Maruyama, Shuntaro Makino, Yoshimitsu SAKAI, Yoshinobu Kubota
-
Publication number: 20210325761Abstract: 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: ApplicationFiled: February 8, 2021Publication date: October 21, 2021Applicant: Fujitsu Optical Components LimitedInventors: Shuntaro MAKINO, Yoshinobu KUBOTA, Yasuhiro OHMORI, Masaharu DOI, Shintaro TAKEUCHI
-
Publication number: 20210325760Abstract: 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: ApplicationFiled: February 2, 2021Publication date: October 21, 2021Applicant: Fujitsu Optical Components LimitedInventors: Shuntaro Makino, Yoshinobu Kubota, Yasuhiro Ohmori, Masaharu Doi, Teruo Kurahashi, Shintaro Takeuchi
-
Patent number: 11086149Abstract: 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: GrantFiled: March 27, 2020Date of Patent: August 10, 2021Assignees: TDK CORPORATION, FUJITSU OPTICAL COMPONENTS LIMITEDInventors: Shinji Iwatsuka, Kenji Sasaki, Hiroki Hara, Yasuhiro Ohmori, Masaharu Doi, Shintaro Takeuchi, Yoshihiko Yoshida, Yoshinobu Kubota
-
Patent number: 11003043Abstract: 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: GrantFiled: February 24, 2020Date of Patent: May 11, 2021Assignee: TDK CORPORATIONInventors: Yasuhiro Ohmori, Masaharu Doi, Shintaro Takeuchi, Takehito Tanaka, Yoshinobu Kubota, Shinji Iwatsuka, Kenji Endou, Hiroki Hara, Toshinori Matsuura, Takashi Kikukawa
-
Patent number: 11003044Abstract: 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: GrantFiled: February 24, 2020Date of Patent: May 11, 2021Assignees: TDK CORPORATION, FUJITSU OPTICAL COMPONENTS LIMITEDInventors: Hiroki Hara, Shinji Iwatsuka, Takashi Kikukawa, Toshinori Matsuura, Yasuhiro Ohmori, Masaharu Doi, Shintaro Takeuchi, Yoshinobu Kubota
-
Patent number: 10989980Abstract: 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: GrantFiled: February 24, 2020Date of Patent: April 27, 2021Assignees: TDK CORPORATION, FUJITSU OPTICAL COMPONENTS LIMITEDInventors: Shinji Iwatsuka, Kenji Endou, Hiroki Hara, Toshinori Matsuura, Takashi Kikukawa, Yasuhiro Ohmori, Masaharu Doi, Shintaro Takeuchi, Takehito Tanaka, Yoshinobu Kubota
-
Publication number: 20210103165Abstract: 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: ApplicationFiled: March 27, 2020Publication date: April 8, 2021Inventors: Shinji IWATSUKA, Kenji SASAKI, Hiroki HARA, Yasuhiro OHMORI, Masaharu DOI, Shintaro TAKEUCHI, Yoshihiko YOSHIDA, Yoshinobu KUBOTA
-
Publication number: 20200310216Abstract: 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: ApplicationFiled: March 27, 2020Publication date: October 1, 2020Inventors: Shinji IWATSUKA, Kenji SASAKI, Hiroki HARA, Yasuhiro OHMORI, Masaharu DOI, Shintaro TAKEUCHI, Yoshihiko YOSHIDA, Yoshinobu KUBOTA
-
Publication number: 20200272020Abstract: 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: ApplicationFiled: February 24, 2020Publication date: August 27, 2020Inventors: Yasuhiro OHMORI, Masaharu DOI, Shintaro TAKEUCHI, Takehito TANAKA, Yoshinobu KUBOTA, Shinji IWATSUKA, Kenji ENDOU, Hiroki HARA, Toshinori MATSUURA, Takashi KIKUKAWA
-
Publication number: 20200271963Abstract: 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: ApplicationFiled: February 24, 2020Publication date: August 27, 2020Inventors: Shinji Iwatsuka, Kenji Endou, Hiroki Hara, Toshinori Matsuura, Takashi Kikukawa, Yasuhiro Ohmori, Masaharu Doi, Shintaro Takeuchi, Takehito Tanaka, Yoshinobu Kubota
-
Publication number: 20200272021Abstract: 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: ApplicationFiled: February 24, 2020Publication date: August 27, 2020Applicant: FUJITSU OPTICAL COMPONENTS LIMITEDInventors: Hiroki HARA, Shinji IWATSUKA, Takashi KIKUKAWA, Toshinori MATSUURA, Yasuhiro OHMORI, Masaharu DOI, Shintaro TAKEUCHI, Yoshinobu KUBOTA
-
Patent number: 10754179Abstract: 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: GrantFiled: July 18, 2019Date of Patent: August 25, 2020Assignee: FUJITSU OPTICAL COMPONENTS LIMITEDInventors: Yasuhiro Ohmori, Yoshinobu Kubota, Masaharu Doi, Shintaro Takeuchi, Yoshihiko Yoshida