Patents by Inventor Eishi Kubota

Eishi 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: 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
  • 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
  • Patent number: 7110652
    Abstract: An optical waveguide capable of having various characteristics and a method of manufacture thereof as well as a method of manufacturing a crystal film are provided. An optical functional material KTaxNb1?xO3 is used as an optical waveguide. The input optical signal is transmitted to the KTaxNb1?xO3 film. The KTaxNb1?xO3 film undergoes changes in optical property when an external voltage signal is applied to the electrode. Therefore, as it passes through the KTaxNb1?xO3 film, the input optical signal is modulated by the characteristic change. The modulated optical signal is taken out as an output optical signal.
    Type: Grant
    Filed: September 27, 2005
    Date of Patent: September 19, 2006
    Assignee: Nippon Telegraph & Telephone Corporation
    Inventors: Masahiro Sasaura, Kazuo Fujiura, Koji Enbutsu, Tadayuki Imai, Shogo Yagi, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
  • Patent number: 6996321
    Abstract: An optical waveguide capable of having various characteristics and a method of manufacture thereof as well as a method of manufacturing a crystal film are provided. An optical functional material KTaxNb1-xO3 is used as an optical waveguide. The input optical signal is transmitted to the KTaxNb1-xO3 film. The KTaxNb1-xO3 film undergoes changes in optical property when an external voltage signal is applied to the electrode. Therefore, as it passes through the KTaxNb1-xO3 film, the input optical signal is modulated by the characteristic change. The modulated optical signal is taken out as an output optical signal.
    Type: Grant
    Filed: August 3, 2004
    Date of Patent: February 7, 2006
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Masahiro Sasaura, Kazuo Fujiura, Koji Enbutsu, Tadayuki Imai, Shogo Yagi, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
  • Publication number: 20060018617
    Abstract: An optical waveguide capable of having various characteristics and a method of manufacture thereof as well as a method of manufacturing a crystal film are provided. An optical functional material KTaxNb1-xO3 is used as an optical waveguide. The input optical signal is transmitted to the KTaxNb1-xO3 film. The KTaxNb1-xO3 film undergoes changes in optical property when an external voltage signal-is applied to the electrode. Therefore, as it passes through the KTaxNb1-xO3 film, the input optical signal is modulated by the characteristic change. The modulated optical signal is taken out as an output optical signal.
    Type: Application
    Filed: September 27, 2005
    Publication date: January 26, 2006
    Applicant: Nippon Telegraph and Telephone Corporation
    Inventors: Masahiro Sasaura, Kazuo Fujiura, Koji Enbutsu, Tadayuki Imai, Shogo Yagi, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
  • Publication number: 20060018616
    Abstract: An optical waveguide capable of having various characteristics and a method of manufacture thereof as well as a method of manufacturing a crystal film are provided. An optical functional material KTaxNb1-xO3 is used as an optical waveguide. The input optical signal is transmitted to the KTaxNb1-xO3 film. The KTaxNb1-xO3 film undergoes changes in optical property when an external voltage signal is applied to the electrode. Therefore, as it passes through the KTaxNb1-xO3 film, the input optical signal is modulated by the characteristic change. The modulated optical signal is taken out as an output optical signal.
    Type: Application
    Filed: September 27, 2005
    Publication date: January 26, 2006
    Applicant: Nippon Telegraph and Telephone Corporation
    Inventors: Masahiro Sasaura, Kazuo Fujiura, Koji Enbutsu, Tadayuki Imai, Shogo Yagi, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
  • 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
  • Publication number: 20050008318
    Abstract: An optical waveguide capable of having various characteristics and a method of manufacture thereof as well as a method of manufacturing a crystal film are provided. An optical functional material KTaxNb1-xO3 is used as an optical waveguide. The input optical signal is transmitted to the KTaxNb1-xO3 film. The KTaxNb1-xO3 film undergoes changes in optical property when an external voltage signal is applied to the electrode. Therefore, as it passes through the KTaxNb1-xO3 film, the input optical signal is modulated by the characteristic change. The modulated optical signal is taken out as an output optical signal.
    Type: Application
    Filed: August 3, 2004
    Publication date: January 13, 2005
    Applicant: Nippon Telegraph and Telephone Corporation
    Inventors: Masahiro Sasaura, Kazuo Fujiura, Koji Enbutsu, Tadayuki Imai, Shogo Yagi, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
  • Patent number: 6795232
    Abstract: A wavelength converter implements high speed, high efficiency, low noise wavelength conversion without performing high voltage poling of a crystal, and enables switching and modulation of converted light in response to an electric field. A KLTN crystal, includes a deposited-gold electrode within its incidence plane, and is connected to a DC power supply via a copper wire. The crystal material is composed of KTa1-xNbxO3 and/or K1-yLiyTa1-xNbxO3. A polarizer controls the polarization of the fundamental wave in the direction parallel to the electric field, and launches it into the electrode of the KLTN crystal. The KLTN crystal, rotating on an axis in the direction of the electric field, launches only part of the generated SHG light with the same polarization direction as that of the incident light into a photo multiplier tube through a polarizer.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: September 21, 2004
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Kazuo Fujiura, Shogo Yagi, Tadayuki Imai, Koji Enbutsu, Masahiro Sasaura, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
  • Patent number: 6792189
    Abstract: An optical waveguide capable of having various characteristics and a method of manufacture thereof as well as a method of manufacturing a crystal film are provided. An optical functional material KTaxNb1-xO3 is used as an optical waveguide. The input optical signal is transmitted to the KTaxNb1-xO3 film. The KTaxNb1-xO3 film undergoes changes in optical property when an external voltage signal is applied to the electrode. Therefore, as it passes through the KTaxNb1-xO3 film, the input optical signal is modulated by the characteristic change. The modulated optical signal is taken out as an output optical signal.
    Type: Grant
    Filed: May 13, 2002
    Date of Patent: September 14, 2004
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Masahiro Sasaura, Kazuo Fujiura, Koji Enbutsu, Tadayuki Imai, Shogo Yagi, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
  • Publication number: 20030072550
    Abstract: An optical waveguide capable of having various characteristics and a method of manufacture thereof as well as a method of manufacturing a crystal film are provided. An optical functional material KTaxNb1−xO3 is used as an optical waveguide. The input optical signal is transmitted to the KTaxNb1−xO3 film. The KTaxNb1−xO3 film undergoes changes in optical property when an external voltage signal is applied to the electrode. Therefore, as it passes through the KTaxNb1−xO3 film, the input optical signal is modulated by the characteristic change. The modulated optical signal is taken out as an output optical signal.
    Type: Application
    Filed: May 13, 2002
    Publication date: April 17, 2003
    Inventors: Masahiro Sasaura, Kazuo Fujiura, Koji Enbutsu, Tadayuki Imai, Shogo Yagi, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
  • Publication number: 20020141040
    Abstract: A wavelength converter implements high speed, high efficiency, low noise wavelength conversion without performing high voltage poling of a crystal, and enables switching and modulation of converted light in response to an electric field. A KLTN crystal, includes a deposited-gold electrode within its incidence plane, and is connected to a DC power supply via a copper wire. The crystal material is composed of KTa1-xNbxO3 and/or K1-yLiyTa1-xNbxO3. A polarizer controls the polarization of the fundamental wave in the direction parallel to the electric field, and launches it into the electrode of the KLTN crystal. The KLTN crystal, rotating on an axis in the direction of the electric field, launches only part of the generated SHG light with the same polarization direction as that of the incident light into a photo multiplier tube through a polarizer.
    Type: Application
    Filed: March 29, 2002
    Publication date: October 3, 2002
    Inventors: Kazuo Fujiura, Shogo Yagi, Tadayuki Imai, Koji Enbutsu, Masahiro Sasaura, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
  • Patent number: 4018570
    Abstract: A composite of a metallic material and vulcanized rubber is produced by contacting an unvulcanized rubber with a metallic material coated with a ternary alloy composed of copper, zinc and tin.
    Type: Grant
    Filed: January 30, 1976
    Date of Patent: April 19, 1977
    Assignee: Bridgestone Tire Company Limited
    Inventors: Yuzuru Nakamoto, Eishi Kubota, Fukushi Suzuki
  • Patent number: 3961740
    Abstract: A composite of a metallic material and vulcanized rubber is produced by contacting an unvulcanized rubber with a metallic material coated with a ternary alloy composed of copper, zinc and tin.
    Type: Grant
    Filed: March 4, 1974
    Date of Patent: June 8, 1976
    Assignee: Bridgestone Tire Company Limited
    Inventors: Yuzuru Nakamoto, Eishi Kubota, Fukushi Suzuki