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).
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Patent number: 7573921Abstract: 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: GrantFiled: August 15, 2007Date of Patent: August 11, 2009Assignee: Nippon Telegraph and Telephone CorporationInventors: Junji Yumoto, Osamu Tadanaga, Masaki Asobe, Hiroyuki Suzuki, Kaoru Yoshino, Hiroshi Miyazawa, Yoshiki Nishida, Hirohisa Kanbara, Tsutomu Yanagawa, Eishi Kubota, Hiroyasu Mawatari
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Patent number: 7391795Abstract: 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: GrantFiled: July 30, 2004Date of Patent: June 24, 2008Assignee: Nippon Telegraph and Telephone CorporationInventors: Junji Yumoto, Osamu Tadanaga, Masaki Asobe, Hiroyuki Suzuki, Kaoru Yoshino, Hiroshi Miyazawa, Yoshiki Nishida, Hirohisa Kanbara, Tsutomu Yanagawa, Eishi Kubota, Hiroyasu Mawatari
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Publication number: 20070297465Abstract: 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: ApplicationFiled: August 15, 2007Publication date: December 27, 2007Applicant: Nippon Telegraph and Telephone CorporationInventors: Junji Yumoto, Osamu Tadanaga, Masaki Asobe, Hiroyuki Suzuki, Kaoru Yoshino, Hiroshi Miyazawa, Yoshiki Nishida, Hirohisa Kanbara, Tsutomu Yanagawa, Eishi Kubota, Hiroyasu Mawatari
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Patent number: 7110652Abstract: 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: GrantFiled: September 27, 2005Date of Patent: September 19, 2006Assignee: Nippon Telegraph & Telephone CorporationInventors: Masahiro Sasaura, Kazuo Fujiura, Koji Enbutsu, Tadayuki Imai, Shogo Yagi, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
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Patent number: 6996321Abstract: 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: GrantFiled: August 3, 2004Date of Patent: February 7, 2006Assignee: Nippon Telegraph and Telephone CorporationInventors: Masahiro Sasaura, Kazuo Fujiura, Koji Enbutsu, Tadayuki Imai, Shogo Yagi, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
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Publication number: 20060018617Abstract: 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: ApplicationFiled: September 27, 2005Publication date: January 26, 2006Applicant: Nippon Telegraph and Telephone CorporationInventors: Masahiro Sasaura, Kazuo Fujiura, Koji Enbutsu, Tadayuki Imai, Shogo Yagi, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
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Publication number: 20060018616Abstract: 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: ApplicationFiled: September 27, 2005Publication date: January 26, 2006Applicant: Nippon Telegraph and Telephone CorporationInventors: Masahiro Sasaura, Kazuo Fujiura, Koji Enbutsu, Tadayuki Imai, Shogo Yagi, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
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Publication number: 20060013270Abstract: 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: ApplicationFiled: July 30, 2004Publication date: January 19, 2006Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Junji Yumoto, Osamu Tadanaga, Masaki Asobe, Hiroyuki Suzuki, Kaoru Yoshino, Hiroshi Miyazawa, Yoshiki Nishida, Hirohisa Kanbara, Tsutomu Yanagawa, Eishi Kubota, Hiroyasu Mawatari
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Publication number: 20050008318Abstract: 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: ApplicationFiled: August 3, 2004Publication date: January 13, 2005Applicant: Nippon Telegraph and Telephone CorporationInventors: Masahiro Sasaura, Kazuo Fujiura, Koji Enbutsu, Tadayuki Imai, Shogo Yagi, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
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Patent number: 6795232Abstract: 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: GrantFiled: March 29, 2002Date of Patent: September 21, 2004Assignee: Nippon Telegraph and Telephone CorporationInventors: Kazuo Fujiura, Shogo Yagi, Tadayuki Imai, Koji Enbutsu, Masahiro Sasaura, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
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Patent number: 6792189Abstract: 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: GrantFiled: May 13, 2002Date of Patent: September 14, 2004Assignee: Nippon Telegraph and Telephone CorporationInventors: Masahiro Sasaura, Kazuo Fujiura, Koji Enbutsu, Tadayuki Imai, Shogo Yagi, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
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Publication number: 20030072550Abstract: 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: ApplicationFiled: May 13, 2002Publication date: April 17, 2003Inventors: Masahiro Sasaura, Kazuo Fujiura, Koji Enbutsu, Tadayuki Imai, Shogo Yagi, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
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Publication number: 20020141040Abstract: 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: ApplicationFiled: March 29, 2002Publication date: October 3, 2002Inventors: Kazuo Fujiura, Shogo Yagi, Tadayuki Imai, Koji Enbutsu, Masahiro Sasaura, Takashi Kurihara, Makoto Abe, Seiji Toyoda, Eishi Kubota
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Patent number: 4018570Abstract: 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: GrantFiled: January 30, 1976Date of Patent: April 19, 1977Assignee: Bridgestone Tire Company LimitedInventors: Yuzuru Nakamoto, Eishi Kubota, Fukushi Suzuki
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Patent number: 3961740Abstract: 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: GrantFiled: March 4, 1974Date of Patent: June 8, 1976Assignee: Bridgestone Tire Company LimitedInventors: Yuzuru Nakamoto, Eishi Kubota, Fukushi Suzuki