Patents by Inventor Rei Hashimoto

Rei Hashimoto 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).

  • Publication number: 20080317081
    Abstract: It makes possible to inject a current into the current confinement region substantially uniformly. A surface emitting type optical semiconductor device includes a semiconductor active layer provided above a substrate; a first and second reflecting mirror layers sandwiching the semiconductor active layer to form an optical cavity in a direction perpendicular to the substrate; a plurality of current confinement regions provided in the second reflecting mirror layer so as to be separated by an impurity region having impurities; a semiconductor current diffusion layer provided on the second reflecting mirror layer so as to cover the current confinement regions; and an electrode portion which injects a current into the semiconductor active layer. The electrode portion comprising a first electrode provided on the semiconductor current diffusion layer so as to surround the current confinement regions and a second electrode provided on an opposite side of the substrate from the semiconductor active layer.
    Type: Application
    Filed: August 13, 2008
    Publication date: December 25, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Mitsuhiro Kushibe, Mizunori Ezaki, Rei Hashimoto, Michihiko Nishigaki
  • Patent number: 7426228
    Abstract: It makes possible to inject a current into the current confinement region substantially uniformly. A surface emitting type optical semiconductor device includes a semiconductor active layer provided above a substrate; a first and second reflecting mirror layers sandwiching the semiconductor active layer to form an optical cavity in a direction perpendicular to the substrate; a plurality of current confinement regions provided in the second reflecting mirror layer so as to be separated by an impurity region having impurities; a semiconductor current diffusion layer provided on the second reflecting mirror layer so as to cover the current confinement regions; and an electrode portion which injects a current into the semiconductor active layer. The electrode portion comprising a first electrode provided on the semiconductor current diffusion layer so as to surround the current confinement regions and a second electrode provided on an opposite side of the substrate from the semiconductor active layer.
    Type: Grant
    Filed: March 23, 2006
    Date of Patent: September 16, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mitsuhiro Kushibe, Mizunori Ezaki, Rei Hashimoto, Michihiko Nishigaki
  • Patent number: 7276735
    Abstract: A low-cost high-property optical semiconductor element for a long wavelength is provided, using a GaAs substrate. The optical semiconductor element comprises a substrate of GaAs having a first surface and a second surface opposite to each other, a buffer layer of InjGa1-jAs1-kNk (0?j?1, 0.002?k?0.05) formed on the first surface of the substrate, a first conductive type clad layer formed on the buffer layer, an active layer formed on the first conductive type clad layer and comprising a well layer of InzGa1-zAs (0?z?1), the well layer having a smaller bandgap than the first conductive type clad layer, the active layer having a thickness of more than its critical thickness for the substrate based upon equilibrium theories, and a second conductive type clad layer formed on the active layer and having a larger bandgap than the well layer.
    Type: Grant
    Filed: July 2, 2004
    Date of Patent: October 2, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mitsuhiro Kushibe, Yasuo Ohba, Rei Hashimoto, Keiji Takaoka
  • Publication number: 20070047607
    Abstract: It makes possible to inject a current into the current confinement region substantially uniformly. A surface emitting type optical semiconductor device includes a semiconductor active layer provided above a substrate; a first and second reflecting mirror layers sandwiching the semiconductor active layer to form an optical cavity in a direction perpendicular to the substrate; a plurality of current confinement regions provided in the second reflecting mirror layer so as to be separated by an impurity region having impurities; a semiconductor current diffusion layer provided on the second reflecting mirror layer so as to cover the current confinement regions; and an electrode portion which injects a current into the semiconductor active layer. The electrode portion comprising a first electrode provided on the semiconductor current diffusion layer so as to surround the current confinement regions and a second electrode provided on an opposite side of the substrate from the semiconductor active layer.
    Type: Application
    Filed: March 23, 2006
    Publication date: March 1, 2007
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Mitsuhiro Kushibe, Mizunori Ezaki, Rei Hashimoto, Michihiko Nishigaki
  • Publication number: 20040245536
    Abstract: A low-cost high-property optical semiconductor element for a long wavelength is provided, using a GaAs substrate. The optical semiconductor element comprises a substrate of GaAs having a first surface and a second surface opposite to each other, a buffer layer of InjGa1-jAs1-kNk (0≦j≦1, 0.002≦k≦0.05) formed on the first surface of the substrate, a first conductive type clad layer formed on the buffer layer, an active layer formed on the first conductive type clad layer and comprising a well layer of InzGa1-zAs (0≦z≦1), the well layer having a smaller bandgap than the first conductive type clad layer, the active layer having a thickness of more than its critical thickness for the substrate based upon equilibrium theories, and a second conductive type clad layer formed on the active layer and having a larger bandgap than the well layer.
    Type: Application
    Filed: July 2, 2004
    Publication date: December 9, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Mitsuhiro Kushibe, Yasuo Ohba, Rei Hashimoto, Keiji Takaoka
  • Patent number: 6768137
    Abstract: A low-cost high-property optical semiconductor element for a long wavelength is provided, using a GaAs substrate. The optical semiconductor element comprises a substrate of GaAs having a first surface and a second surface opposite to each other, a buffer layer of InjGa1-jAs1-kNk (0≦j≦1, 0.002≦k≦0.05) formed on the first surface of the substrate, a first conductive type clad layer formed on the buffer layer, an active layer formed on the first conductive type clad layer and comprising a well layer of InzGa1-zAs (0≦z≦1), the well layer having a smaller bandgap than the first conductive type clad layer, the active layer having a thickness of more than its critical thickness for the substrate based upon equilibrium theories, and a second conductive type clad layer formed on the active layer and having a larger bandgap than the well layer.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: July 27, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mitsuhiro Kushibe, Yasuo Ohba, Rei Hashimoto, Keiji Takaoka
  • Publication number: 20030183837
    Abstract: A low-cost high-property optical semiconductor element for a long wavelength is provided, using a GaAs substrate. The optical semiconductor element comprises a substrate of GaAs having a first surface and a second surface opposite to each other, a buffer layer of InjGa1−jAs1−kNk (0≦j≦1, 0.002≦k≦0.05) formed on the first surface of the substrate, a first conductive type clad layer formed on the buffer layer, an active layer formed on the first conductive type clad layer and comprising a well layer of InzGa1−zAs (0≦z≦1), the well layer having a smaller bandgap than the first conductive type clad layer, the active layer having a thickness of more than its critical thickness for the substrate based upon equilibrium theories, and a second conductive type clad layer formed on the active layer and having a larger bandgap than the well layer.
    Type: Application
    Filed: March 28, 2003
    Publication date: October 2, 2003
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Mitsuhiro Kushibe, Yasuo Ohba, Rei Hashimoto, Keiji Takaoka