Patents by Inventor Harumi Namba

Harumi Namba 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).

  • Method of making a semiconductor laser using superlattice disordering
    Patent number: 4957879
    Abstract: A buried heterojunction semiconductor laser appropriate for integration with other electronic circuitry and method of producing same, in which the width of a central stripe of the active region can be reduced beyond the physical size limitations of the connecting electrode so as to allow the semiconductor laser to oscillate in a stable manner and with low threshold current. The semiconductor laser is provided with a portion of the surface of the upper cladding layer located above the disordered active layer regions electrically connected with the upper cladding layer located above the nondisordered central stripe. As a result, the central stripe electrode can be of a width larger than that of the central stripe itself.
    Type: Grant
    Filed: September 22, 1989
    Date of Patent: September 18, 1990
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Etsuji Omura, Katsuhiko Goto, Shogo Takahashi, Harumi Namba, Akira Takemoto
  • Semiconductor laser
    Patent number: 4888781
    Abstract: A buried heterojunction semiconductor laser appropriate for integration with other electronic circuitry and method of producing same, in which the width of a central stripe of the active region can be reduced beyond the physical size limitations of the connecting electrode so as to allow the semiconductor laser to oscillate in a stable manner and with low threshold current. The semiconductor laser is provided with a portion of the surface of the upper cladding layer located above the disordered active layer regions electrically connected with the upper cladding layer located above the nondisordered central stripe. As a result, the central stripe electrode can be of a width larger than that of the central stripe itself.
    Type: Grant
    Filed: January 31, 1989
    Date of Patent: December 19, 1989
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Etsuji Omura, Katsuhiko Goto, Shogo Takahashi, Harumi Namba, Akira Takemoto