Patents by Inventor Shigehiro Nagano

Shigehiro Nagano 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: 10962709
    Abstract: An optical fiber according to an embodiment includes a core having a single-peaked and graded refractive index profile, an inner cladding surrounding the core, and an outer cladding surrounding the inner cladding. The inner and outer claddings have refractive indices lower than the maximum refractive index of the core. A photosensitive region constituted by the core and the inner cladding contains a photosensitive material. The inner cladding has an outer diameter one time or more and two times or less the MFD of an LP01 mode in a 1310-nm wavelength band.
    Type: Grant
    Filed: September 10, 2020
    Date of Patent: March 30, 2021
    Assignees: SUMITOMO ELECTRIC INDUSTRIES, LTD., SUMITOMO ELECTRIC OPTIFRONTIER CO., LTD.
    Inventors: Shigehiro Nagano, Masakazu Shigehara, Masayuki Yamazaki
  • Publication number: 20210088725
    Abstract: A method for manufacturing an optical device includes a hydrogen-loading step, a laser irradiation step, and a light condensing point movement step. A continuous refractive index changed region is formed in a glass member by alternately repeating the laser irradiation step and the light condensing point movement step or performing the laser irradiation step and the light condensing point movement step in parallel. In the hydrogen-loading step, hydrogen is loaded into the glass member containing P2O5 as a main component. In the laser irradiation step, a femtosecond laser beam having a repetition frequency of 10 kHz or higher is condensed in the hydrogen-loaded glass member, and a light-induced change in refractive index is caused in the glass member. In the light condensing point movement step, a light condensing point position of the femtosecond laser beam is moved relative to the glass member.
    Type: Application
    Filed: November 16, 2020
    Publication date: March 25, 2021
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Shigehiro NAGANO
  • Publication number: 20210080650
    Abstract: A method for manufacturing an optical device includes a hydrogen-loading step, a laser irradiation step, and a light condensing point movement step. The laser irradiation step and the light condensing point movement step are alternately repeated, or are performed in parallel. In the hydrogen-loading step, hydrogen is loaded into a glass member containing B2O3 and has a content of GeO2 less than 10% by mass fraction based on an oxide. In the laser irradiation step, a femtosecond laser beam having a repetition frequency of 10 kHz or higher is condensed and emitted into the glass member into which the hydrogen is loaded, and a light-induced change in refractive index is caused in the glass member. In the light condensing point movement step, a light condensing point position of the femtosecond laser beam is moved relative to the glass member.
    Type: Application
    Filed: November 16, 2020
    Publication date: March 18, 2021
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Shigehiro NAGANO
  • Publication number: 20210048580
    Abstract: A method for manufacturing an optical device includes: a laser irradiation step of condensing pulsed first laser light and pulsed second laser light to the inside of a glass member including germanium and titanium; and a condensing position movement step of moving condensing positions relatively to the glass member. Each of the first laser light and the second laser light has a repetition frequency of 10 kHz or greater. The first laser light is condensed to a dot-shaped condensing region, and the second laser light is condensed to an annular condensing region surrounding the condensing region of the first laser light. A central wavelength of the first laser light is greater than 400 nm and equal to or less than 700 nm, and a central wavelength of the second laser light is equal to or greater than 800 nm and equal to or less than 1100 nm.
    Type: Application
    Filed: November 3, 2020
    Publication date: February 18, 2021
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Shigehiro Nagano
  • Patent number: 10908353
    Abstract: An optical fiber is made of silica-based glass and includes a core, a first cladding that surrounds the core and that has a refractive index lower than a refractive index of the core; and a second cladding that surrounds the first cladding and that has a refractive index lower than the refractive index of the core and higher than the refractive index of the first cladding. At least a part of the first cladding contains a photosensitive material whose refractive index increases by irradiation with light having a specific wavelength. A difference ?n between a refractive index of a portion of the first cladding, the portion being nearest to the core, and the refractive index of the core is in a range of 0.25% to 0.30%. The radius ra of the core is larger than 4.3 ?m and smaller than or equal to 5.0 ?m.
    Type: Grant
    Filed: November 16, 2018
    Date of Patent: February 2, 2021
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shigehiro Nagano, Manabu Shiozaki, Jun Kinugasa, Takemi Hasegawa
  • Publication number: 20210026222
    Abstract: A wavelength conversion optical device includes: a substrate having a virtual plane and first and second regions and including multiple first crystal regions and multiple second crystal regions. Each of the multiple first crystal regions includes a pair of portions arranged in a direction intersecting a first plane with the first plane interposed therebetween, the first plane being located in the first region, and directions of spontaneous polarizations of each of the pair of portions being directions away from the first plane. Each of the multiple second crystal regions includes a pair of portions arranged in a direction intersecting a second plane with the second plane interposed therebetween, the second plane being located in the second region. Directions of spontaneous polarizations of each of the pair of portions being directions away from the second plane.
    Type: Application
    Filed: September 30, 2020
    Publication date: January 28, 2021
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Shigehiro NAGANO
  • Publication number: 20200408986
    Abstract: An optical fiber according to an embodiment includes a core having a single-peaked and graded refractive index profile, an inner cladding surrounding the core, and an outer cladding surrounding the inner cladding. The inner and outer claddings have refractive indices lower than the maximum refractive index of the core. A photosensitive region constituted by the core and the inner cladding contains a photosensitive material. The inner cladding has an outer diameter one time or more and two times or less the MFD of an LP01 mode in a 1310-nm wavelength band.
    Type: Application
    Filed: September 10, 2020
    Publication date: December 31, 2020
    Applicants: SUMITOMO ELECTRIC INDUSTRIES, LTD., SUMITOMO ELECTRIC OPTIFRONTIER CO., LTD.
    Inventors: Shigehiro NAGANO, Masakazu SHIGEHARA, Masayuki YAMAZAKI
  • Patent number: 10830948
    Abstract: An embodiment of the invention relates to an optical device which is capable of realizing a secondary nonlinear optical phenomenon. The optical device is a fiber-type optical device which is comprised of glass containing SiO2, and includes a core region, a first cladding region, and a second cladding region. At least a part of a glass region configured by the core region and the first cladding region has such a repetition structure that a first section serving as a poled crystal region and a second section serving as an amorphous region are alternately disposed along a longitudinal direction of the optical device.
    Type: Grant
    Filed: March 31, 2020
    Date of Patent: November 10, 2020
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Shigehiro Nagano
  • Publication number: 20200348578
    Abstract: An optical wavelength converter of one embodiment comprises: a substrate comprised of a crystalline material or an amorphous material; plural first crystal regions each having a radial first polarization-ordered structure; and plural second crystal regions each having a radial second polarization-ordered structure. In the substrate, a first and second regions are defined to be directly adjacent to each other with a virtual axis therebetween when the substrate is viewed from a reference direction orthogonal to the virtual axis. Radial centers of the first polarization-ordered structures located in the first region and radial centers of the second polarization-ordered structures located in the second region are alternately arranged along the virtual axis. The plural first crystal regions partially protrude to the second region. The plural second crystal regions partially protrude to the first region.
    Type: Application
    Filed: July 16, 2020
    Publication date: November 5, 2020
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventors: Shigehiro NAGANO, Takumi Fujiwara, Yoshihiro Takahashi, Nobuaki Terakado
  • Publication number: 20200324376
    Abstract: A method for manufacturing an optical device according to an embodiment comprises: loading hydrogen into a glass member containing Ge; irradiating a laser beam from a femtosecond laser into the glass member having the hydrogen loaded therein, the laser beam having an amount of energy causing a light-induced change in refractive index of the glass member and having a repetition frequency of 10 kHz or higher; and moving a light convergence point position of the laser beam relative to the glass member. A repetition of the irradiating and the moving forms a continuous refractive index changed region in the glass member.
    Type: Application
    Filed: June 26, 2020
    Publication date: October 15, 2020
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shigehiro NAGANO, Tetsu MORISHIMA
  • Publication number: 20200264491
    Abstract: An object is to provide, for example, a method for manufacturing an optical wavelength conversion device having a structure that enables efficient formation of crystal regions on the surface of, or inside, an amorphous material. An amorphous main body is intermittently irradiated with a first laser beam for generating a high-density excited electron region inside the main body and a second laser beam for heating the high-density excited electron region, with respective focus regions of the first and second laser beams overlapping each other. During the intermittent irradiation with the first and second laser beams, the relative position of the main body and the overlapping focus region of the first and second laser beams are varied. This enables part of the main body where the overlapping focus region moves to serve as a heat source for forming a crystal region.
    Type: Application
    Filed: May 7, 2020
    Publication date: August 20, 2020
    Inventor: Shigehiro NAGANO
  • Publication number: 20200225408
    Abstract: An embodiment of the invention relates to an optical device which is capable of realizing a secondary nonlinear optical phenomenon. The optical device is a fiber-type optical device which is comprised of glass containing SiO2, and includes a core region, a first cladding region, and a second cladding region. At least a part of a glass region configured by the core region and the first cladding region has such a repetition structure that a first section serving as a poled crystal region and a second section serving as an amorphous region are alternately disposed along a longitudinal direction of the optical device.
    Type: Application
    Filed: March 31, 2020
    Publication date: July 16, 2020
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventor: Shigehiro NAGANO
  • Publication number: 20200218127
    Abstract: An object is to provide, for example, a method for manufacturing an optical wavelength conversion device having a structure that enables efficient formation of crystal regions on the surface of, or inside, an amorphous material. An amorphous main body is intermittently irradiated with a first laser beam for generating a high-density excited electron region inside the main body and a second laser beam for heating the high-density excited electron region, with respective focus regions of the first and second laser beams overlapping each other. During the intermittent irradiation with the first and second laser beams, the relative position of the main body and the overlapping focus region of the first and second laser beams are varied. This enables part of the main body where the overlapping focus region moves to serve as a heat source for forming a crystal region.
    Type: Application
    Filed: December 10, 2019
    Publication date: July 9, 2020
    Inventor: Shigehiro NAGANO
  • Patent number: 10698292
    Abstract: An object is to provide, for example, a method for manufacturing an optical wavelength conversion device having a structure that enables efficient formation of crystal regions on the surface of, or inside, an amorphous material. An amorphous main body is intermittently irradiated with a first laser beam for generating a high-density excited electron region inside the main body and a second laser beam for heating the high-density excited electron region, with respective focus regions of the first and second laser beams overlapping each other. During the intermittent irradiation with the first and second laser beams, the relative position of the main body and the overlapping focus region of the first and second laser beams are varied. This enables part of the main body where the overlapping focus region moves to serve as a heat source for forming a crystal region.
    Type: Grant
    Filed: December 10, 2019
    Date of Patent: June 30, 2020
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Shigehiro Nagano
  • Patent number: 10663656
    Abstract: An embodiment of the invention relates to an optical device which is capable of realizing a secondary nonlinear optical phenomenon. The optical device is a fiber-type optical device which is comprised of glass containing SiO2, and includes a core region, a first cladding region, and a second cladding region. At least a part of a glass region configured by the core region and the first cladding region has such a repetition structure that a first section serving as a poled crystal region and a second section serving as an amorphous region are alternately disposed along a longitudinal direction of the optical device.
    Type: Grant
    Filed: June 21, 2018
    Date of Patent: May 26, 2020
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Shigehiro Nagano
  • Patent number: 10605982
    Abstract: The present embodiment relates to an MCF and the like suitable for fabricating an FBG with improved ripple characteristics. The MCF is mainly composed of silica glass, and comprises a plurality of light guiding structures and a common cladding. Each of the light guiding structures includes a core, a first cladding, and a second cladding. The refractive index of the second cladding is higher than that of the first cladding and is lower than those of the core and the common cladding. Further, at least a part of an inner cladding region, constituted by the first cladding and the second cladding, contains a photosensitive material having photosensitivity of changing a refractive index of a glass region containing the photosensitive material in response to irradiation of light with a specific wavelength.
    Type: Grant
    Filed: October 5, 2018
    Date of Patent: March 31, 2020
    Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Shigehiro Nagano
  • Publication number: 20190317380
    Abstract: The present embodiment relates to an optical device or the like that is high in non-linearity and resistance to UV light and includes a structure allowing stable wavelength conversion. The optical device is comprised of glass containing SiO2 and comprises a repetitive structure including first sections being crystallized regions in which a radial polarization-ordered structure is formed and second sections being non-crystallized regions alternately arranged along a center axis extending from a center of a light-incidence end face toward a center of a light-emission end face.
    Type: Application
    Filed: June 25, 2019
    Publication date: October 17, 2019
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventors: Shigehiro NAGANO, Masato SUZUKI, Masato TANAKA, Manabu SHIOZAKI, Hiroo KANAMORI
  • Publication number: 20190207358
    Abstract: The present embodiment relates to an optical amplifier and the like having a structure for enabling efficient use of pumping light while avoiding complication of a device structure. In such an optical amplifier, since pumping light from a pumping light source is supplied to each core of an amplification MCF, a coupling MCF in which adjacent cores form a coupled core is arranged between the amplification MCF and the pumping light source. The pumping light source is optically connected to a specific core of the coupling MCF, and pumping light is coupled from the specific core to remaining cores except the specific core in the coupling MCF before pumping light is supplied to each core of the amplification MCF. This enables coupling of pumping light between optically connected cores between the amplification MCF and the coupling MCF.
    Type: Application
    Filed: March 6, 2019
    Publication date: July 4, 2019
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Takemi HASEGAWA, Tetsuya HAYASHI, Yoshiaki TAMURA, Hirotaka SAKUMA, Shigehiro NAGANO
  • Publication number: 20190154912
    Abstract: An optical fiber is made of silica-based glass and includes a core, a first cladding that surrounds the core and that has a refractive index lower than a refractive index of the core; and a second cladding that surrounds the first cladding and that has a refractive index lower than the refractive index of the core and higher than the refractive index of the first cladding. At least a part of the first cladding contains a photosensitive material whose refractive index increases by irradiation with light having a specific wavelength. A difference ?n between a refractive index of a portion of the first cladding, the portion being nearest to the core, and the refractive index of the core is in a range of 0.25% to 0.30%. The radius ra of the core is larger than 4.3 ?m and smaller than or equal to 5.0 ?m.
    Type: Application
    Filed: November 16, 2018
    Publication date: May 23, 2019
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Shigehiro NAGANO, Manabu SHIOZAKI, Jun KINUGASA, Takemi HASEGAWA
  • Publication number: 20190041575
    Abstract: The present embodiment relates to an MCF and the like suitable for fabricating an FBG with improved ripple characteristics. The MCF is mainly composed of silica glass, and comprises a plurality of light guiding structures and a common cladding. Each of the light guiding structures includes a core, a first cladding, and a second cladding. The refractive index of the second cladding is higher than that of the first cladding and is lower than those of the core and the common cladding. Further, at least a part of an inner cladding region, constituted by the first cladding and the second cladding, contains a photosensitive material having photosensitivity of changing a refractive index of a glass region containing the photosensitive material in response to irradiation of light with a specific wavelength.
    Type: Application
    Filed: October 5, 2018
    Publication date: February 7, 2019
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Shigehiro Nagano