Patents by Inventor Yasuhiko Tsuburai

Yasuhiko Tsuburai 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: 4987097
    Abstract: A gain waveguide type semiconductor laser oscillating visible light has an N type GaAs substrate of, and a double-heterostructure provided above the substrate to include an InGaP active layer, and first and second cladding layers sandwiching the active layer. The first cladding layer consists of N type InGaAlP, whereas the second cladding layer consists of P type InGaAlP. A P type InGaP layer is formed as an intermediate band-gap layer on the second cladding layer. An N type GaAs current-blocking layer is formed on the intermediate band-gap layer, and has an elongated waveguide opening. A P type GaAs contact layer is formed to cover the current-blocking layer and the opening.
    Type: Grant
    Filed: February 28, 1990
    Date of Patent: January 22, 1991
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichi Nitta, Yukie Nishikawa, Masayuki Ishikawa, Yasuhiko Tsuburai, Yoshihiro Kokubun
  • Patent number: 4922499
    Abstract: A gain waveguide type semiconductor laser oscillating visible light has an N type GaAs substrate of, and a double-heterostructure provided above the substrate to include an InGap active layer, and first and second cladding layers sandwiching the active layer. The first cladding layer consists of N type InGaAlP, whereas the second cladding layer consists of P type InGaAlP. A P type InGaP layer is formed as an intermediate band-gap layer on the second cladding layer. An N type GaAs current-blocking layer is formed on the intermediate band-gap layer, and has an elongated waveguide opening. A P type GaAs contact layer is formed to cover the current-blocking layer and the opening.
    Type: Grant
    Filed: February 9, 1989
    Date of Patent: May 1, 1990
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koichi Nitta, Yukie Nishikawa, Masayuki Ishikawa, Yasuhiko Tsuburai, Yoshihiro Kokubun
  • Patent number: 4855250
    Abstract: A method of manufacturing a semiconductor light emitting device by forming a compound semiconductor structure with homo- or heterojunction therein having a first p-type compound semiconductor crystal layer at the top of the structure, growing a second p-type compound semiconductor crystal layer on the structure in a reactor, wherein, before the beginning of the crystal growth step, a p-type dopant is caused to flow into the reactor in which the structure is placed. In some embodiments, the flow of the p-type dopant continues after the completion of the crystal growth.
    Type: Grant
    Filed: December 28, 1987
    Date of Patent: August 8, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Motoyuki Yamamoto, Yasuhiko Tsuburai