Patents by Inventor Ichiro Seko

Ichiro Seko 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).

  • Light emitting chip and optical communication apparatus using the same
    Patent number: 4779281
    Abstract: This invention relates to a semiconductor laser of a buried-hetero structure. In this semiconductor laser, the side surfaces of an active layer are in contact with a plane having a stable state of interface. As a result, the threshold current value of this semiconductor laser is low, and a stable operation can be obtained without causing any kink (projection) in the current-optical output characteristics. An optical communication system using this semiconductor layer has a low operating current, and can maintain high coupling efficiency with an optical fiber without the occurrence of noise, so that optical communication having high reliability is possible.
    Type: Grant
    Filed: July 23, 1987
    Date of Patent: October 18, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Naka, Ichiro Seko, Shuji Kobayashi, Makoto Haneda
  • Light emitting chip and optical communication apparatus using the same
    Patent number: 4701927
    Abstract: This invention relates to a semiconductor laser of a buried-hetero structure. In this semiconductor laser, the side surfaces of an active layer are in contact with a plane having a stable state of interface. As a result, the threshold current value of this semiconductor laser is low, and a stable operation can be obtained without causing any kink (projection ) in the current-optical output characteristics. An optical communication system using this semiconductor layer has a low operating current, and can maintain high coupling efficiency with an optical fiber without the occurrence of noise, so that optical communication having high reliability is possible.
    Type: Grant
    Filed: January 25, 1985
    Date of Patent: October 20, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Naka, Ichiro Seko, Shuji Kobayashi, Makoto Haneda