Patents by Inventor Junji Yumoto

Junji Yumoto 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).

  • Publication number: 20230368854
    Abstract: A photonic spin register includes: a shift register unit including a magnetic material layer having a shape extending in one direction; and a write unit configured to write spin information into a magnetic domain in the magnetic material layer by transferring information included in an optical signal that is a pulse amplitude-modulated and serial input signal, to a spin state of the magnetic domain in the magnetic material layer by means of a photocurrent corresponding to the optical signal or by irradiation with the optical signal. When a shift current flows through the shift register unit in the one direction, a domain wall is configured to move in the magnetic material layer, thereby allowing the spin information to move and be buffered in the magnetic material layer.
    Type: Application
    Filed: July 19, 2023
    Publication date: November 16, 2023
    Applicant: The University of Tokyo
    Inventors: Satoru Nakatsuji, Junji Yumoto, Ryo Shimano, Masamitsu Hayashi, Mitsuru Takenaka, Yusuke Horinouchi
  • Publication number: 20220048142
    Abstract: The present invention relates to a technique to assess dependence of laser machining on laser light intensity with high accuracy by a simple method. First, machining state information showing a machining state by laser machining at a machining position on a workpiece is acquired. Before or after that, or at the same time as that, intensity distribution information showing intensity distribution of laser light at the machining position is acquired. Dependence of the laser machining of the workpiece on the laser light intensity is assessed based on the acquired machining state information and intensity distribution information. For example, it is possible to acquire a breakage threshold for a workpiece in laser machining in a highly accurate and simply manner.
    Type: Application
    Filed: December 26, 2019
    Publication date: February 17, 2022
    Inventors: Haruyuki SAKURAI, Hiroharu TAMARU, Kuniaki KONISHI, Junji YUMOTO
  • Patent number: 7729585
    Abstract: A light source apparatus with modulation function has a wavelength conversion module (75) composed of a nonlinear optical material with a structure having a nonlinear constant modulated periodically. It outputs a difference frequency or sum frequency produced by multiplexing pumping light from semiconductor laser light sources (71) and (72) with different wavelengths through a WDM coupler (74) and by launching the multiplexed light into the optical waveguide. The semiconductor laser light source (72) includes a diffraction grating. The semiconductor laser light source (71) includes a section for modulating output light emitted from its semiconductor laser, and is connected to an external FBG (73) which has a reflection band narrower than a resonance wavelength spacing determined by the device length of the semiconductor laser. The FBG (73) is supplied with the modulated output.
    Type: Grant
    Filed: January 17, 2006
    Date of Patent: June 1, 2010
    Assignees: NipponTelegraph and Telephone Corporation, NTT Electronics Corporation
    Inventors: Katsuaki Magari, Tsutomu Yanagawa, Yoshiki Nishida, Hiroyasu Mawatari, Osamu Tadanaga, Masaki Asobe, Hiroyuki Suzuki, Hiroshi Miyazawa, Junji Yumoto
  • Publication number: 20100053720
    Abstract: A light source apparatus with modulation function has a wavelength conversion module (75) composed of a nonlinear optical material with a structure having a nonlinear constant modulated periodically. It outputs a difference frequency or sum frequency produced by multiplexing pumping light from semiconductor laser light sources (71) and (72) with different wavelengths through a WDM coupler (74) and by launching the multiplexed light into the optical waveguide. The semiconductor laser light source (72) includes a diffraction grating. The semiconductor laser light source (71) includes a section for modulating output light emitted from its semiconductor laser, and is connected to an external FBG (73) which has a reflection band narrower than a resonance wavelength spacing determined by the device length of the semiconductor laser. The FBG (73) is supplied with the modulated output.
    Type: Application
    Filed: January 17, 2006
    Publication date: March 4, 2010
    Applicants: Nippon Telegraph and Telephone Corporation, NTT Electronics Corporation,
    Inventors: Katsuaki Magari, Tsutomu Yanagawa, Yoshiki Nishida, Hiroyasu Mawatari, Osamu Tadanaga, Masaki Asobe, Hiroyuki Suzuki, Hiroshi Miyazawa, Junji Yumoto
  • Patent number: 7573921
    Abstract: A laser light source is disclosed consisting of first and second lasers that respectively generate laser beams of wavelengths ?1 and ?2. Wavelength ?1 is in the range of 0.9-1.0 ?m. A nonlinear optical crystal uses the laser beams of wavelengths ?1 and ?2 as inputs, and outputs a coherent beam having a wavelength ?3 of a difference frequency that satisfies a relationship of 1/?1?1/?2=1/?3. The nonlinear optical crystal has a periodically poled structure of a single period. The wavelength ?3 of the difference frequency varies between 3.1 ?m and 2.0 ?m when the wavelength ?2 varies between 1.3 ?m and 1.8 ?m.
    Type: Grant
    Filed: August 15, 2007
    Date of Patent: August 11, 2009
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Junji Yumoto, Osamu Tadanaga, Masaki Asobe, Hiroyuki Suzuki, Kaoru Yoshino, Hiroshi Miyazawa, Yoshiki Nishida, Hirohisa Kanbara, Tsutomu Yanagawa, Eishi Kubota, Hiroyasu Mawatari
  • Publication number: 20090022903
    Abstract: The present invention provides a periodically-poled structure with high conversion efficiency and improved manufacturing yield. The method for manufacturing a periodically-poled structure in a second order nonlinear optical crystal having a single domain structure (31) includes the steps of forming a resist pattern (32) which matches a polarization-inverted period on a ?Z surface of the second order nonlinear optical crystal (31), and applying voltage to the ?Z surface as a negative voltage where the resist pattern (32) is formed, and a +Z surface as a positive voltage so as to apply an electric field in the second order nonlinear optical crystal (31), wherein the second order nonlinear optical crystal (31) contains at least one element as a dopant which compensate for the crystal defects.
    Type: Application
    Filed: March 17, 2006
    Publication date: January 22, 2009
    Inventors: Hiroyuki Suzuki, Masaki Asobe, Takeshi Umeki, Yoshiki Nishida, Osamu Tadanaga, Tsutomu Yanagawa, Katsuaki Magari, Hiroyasu Mawatari, Hiroshi Miyazawa, Junji Yumoto
  • Patent number: 7391795
    Abstract: The invention provides a compact laser light source whose wavelength can be designed freely in a wavelength band in which the semiconductor laser has not been put to practical use by combining an efficient nonlinear optical crystal and high-power semiconductor lasers for optical communication. In one embodiment, the laser light source includes: a first laser for generating a laser beam of a wavelength ?1; a second laser for generating a laser beam of a wavelength ?2; and a nonlinear optical crystal that allows the laser beam of wavelength ?1 and the laser beam of wavelength ?2 as inputs and outputs a coherent beam having a wavelength ?3 of a sum frequency that satisfies a relationship of 1/?1+1/?2=1/?3. The wavelength ?3 of the sum frequency is 589.3±2 nm that is equivalent to the sodium D line.
    Type: Grant
    Filed: July 30, 2004
    Date of Patent: June 24, 2008
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Junji Yumoto, Osamu Tadanaga, Masaki Asobe, Hiroyuki Suzuki, Kaoru Yoshino, Hiroshi Miyazawa, Yoshiki Nishida, Hirohisa Kanbara, Tsutomu Yanagawa, Eishi Kubota, Hiroyasu Mawatari
  • Publication number: 20070297465
    Abstract: A laser light source is disclosed consisting of first and second lasers that respectively generate laser beams of wavelengths ?1 and ?2. Wavelength ?1 is in the range of 0.9-1.0 ?m. A nonlinear optical crystal uses the laser beams of wavelengths ?1 and ?2 as inputs, and outputs a coherent beam having a wavelength ?3 of a difference frequency that satisfies a relationship of 1/?1?1/?2=1/?3. The nonlinear optical crystal has a periodically poled structure of a single period. The wavelength ?3 of the difference frequency varies between 3.1 ?m and 2.0 ?m when the wavelength ?2 varies between 1.3 ?m and 1.8 ?m.
    Type: Application
    Filed: August 15, 2007
    Publication date: December 27, 2007
    Applicant: Nippon Telegraph and Telephone Corporation
    Inventors: Junji Yumoto, Osamu Tadanaga, Masaki Asobe, Hiroyuki Suzuki, Kaoru Yoshino, Hiroshi Miyazawa, Yoshiki Nishida, Hirohisa Kanbara, Tsutomu Yanagawa, Eishi Kubota, Hiroyasu Mawatari
  • Publication number: 20060013270
    Abstract: The invention provides a compact laser light source whose wavelength can be designed freely in a wavelength band in which the semiconductor laser has not been put to practical use by combining an efficient nonlinear optical crystal and high-power semiconductor lasers for optical communication. In one embodiment, the laser light source includes: a first laser for generating a laser beam of a wavelength ?1; a second laser for generating a laser beam of a wavelength ?2; and a nonlinear optical crystal that allows the laser beam of wavelength ?1 and the laser beam of wavelength ?2 as inputs and outputs a coherent beam having a wavelength ?3 of a sum frequency that satisfies a relationship of 1/?1+1/?2=1/?3. The wavelength ?3 of the sum frequency is 589.3±2 nm that is equivalent to the sodium D line.
    Type: Application
    Filed: July 30, 2004
    Publication date: January 19, 2006
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Junji Yumoto, Osamu Tadanaga, Masaki Asobe, Hiroyuki Suzuki, Kaoru Yoshino, Hiroshi Miyazawa, Yoshiki Nishida, Hirohisa Kanbara, Tsutomu Yanagawa, Eishi Kubota, Hiroyasu Mawatari