Patents by Inventor Hideo Aoyagi

Hideo Aoyagi 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: 7649921
    Abstract: A laser module includes a semiconductor laser element and a feedback optical component forming an external cavity with the semiconductor laser element. Even if a ratio of a current threshold of the laser module changing according to a polarized state of returned light from the feedback optical component to a current threshold of the semiconductor laser element is in an arbitrary range within a predetermined range, a total value of a relative intensity noise occurring between a first frequency determined according to a cavity length of the external cavity and at least equal to or more than a frequency band of using a laser light and a second frequency calculated by multiplying the first frequency by a predetermined number is equal to or more than ?40 dB.
    Type: Grant
    Filed: November 8, 2004
    Date of Patent: January 19, 2010
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Naoki Hayamizu, Yutaka Ohki, Hideo Aoyagi, Takeshi Koiso, Yuji Yamagata, Kiyofumi Muro
  • Publication number: 20050123012
    Abstract: A laser module includes a semiconductor laser element and a feedback optical component forming an external cavity with the semiconductor laser element. Even if a ratio of a current threshold of the laser module changing according to a polarized state of returned light from the feedback optical component to a current threshold of the semiconductor laser element is in an arbitrary range within a predetermined range, a total value of a relative intensity noise occurring between a first frequency determined according to a cavity length of the external cavity and at least equal to or more than a frequency band of using a laser light and a second frequency calculated by multiplying the first frequency by a predetermined number is equal to or more than ?40 dB.
    Type: Application
    Filed: November 8, 2004
    Publication date: June 9, 2005
    Applicants: The FURUKAWA ELECTRIC CO., LTD., Mitsui Chemicals, Inc.
    Inventors: Naoki Hayamizu, Yutaka Ohki, Hideo Aoyagi, Takeshi Koiso, Yuji Yamagata, Kiyofumi Muro
  • Patent number: 6532107
    Abstract: An optical amplifier of the present invention comprises a pumping light source configured to output a pumping light, an amplifier unit configured to receive the pumping light from said pumping light source and amplify an optical signal that passes therethrough, and an optical fiber disposed between said pumping light source and said amplifier unit, said optical fiber including an optical filter that is configured to attenuate the optical signal from said amplifier unit.
    Type: Grant
    Filed: July 2, 2001
    Date of Patent: March 11, 2003
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Takeharu Yamaguchi, Hideo Aoyagi, Toshiaki Tsuda, Yuichiro Irie, Etsuji Katayama, Takeo Shimizu
  • Publication number: 20020039227
    Abstract: An optical amplifier of the present invention comprises a pumping light source configured to output a pumping light, an amplifier unit configured to receive the pumping light from said pumping light source and amplify an optical signal that passes therethrough, and an optical fiber disposed between said pumping light source and said amplifier unit, said optical fiber including an optical filter that is configured to attenuate the optical signal from said amplifier unit.
    Type: Application
    Filed: July 2, 2001
    Publication date: April 4, 2002
    Applicant: THE FURUKAWA ELECTRIC CO., LTD
    Inventors: Takeharu Yamaguchi, Hideo Aoyagi, Toshiaki Tsuda, Yuichiro Irie, Etsuji Katayama, Takeo Shimizu
  • Patent number: 4236088
    Abstract: A noise-free electronic switching circuit selects one of a pair of audio input signals in an audio system. Each input signal is connected by separate conductors to a single output terminal. The output terminals of two transistors are respectively connected between each conductor and ground. When a manually-operated switch is switched to a first operating condition, an exponentially increasing and an exponentially decreasing control voltage are respectively applied to the bases of a first and a second transistor. When the actuating switch is switched to a second operating condition, an exponentially decreasing and an exponentially increasing control voltage are respectively applied to the bases of the first and the second transistor. In either operating condition, one transistor is turned on and the other is turned off. Thus, only the selected audio signal is delivered to the output terminal; and the other non-selected audio signal is shorted to ground before reaching the output terminal.
    Type: Grant
    Filed: August 14, 1978
    Date of Patent: November 25, 1980
    Assignee: Soundesign Corp.
    Inventors: Harumi Horiuchi, Hideo Aoyagi