Patents by Inventor Niyoko Watanabe

Niyoko Watanabe 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).

  • Double-heterostructure semiconductor with mesa stripe waveguide
    Patent number: 4949349
    Abstract: A double-heterostructure semiconductor laser is disclosed which has a semiconductive substrate of a first conductivity type made of III-V compound semiconductor material, a first semiconductive cladding layer of the first conductivity type disposed above the substrate, an active layer made of a semiconductor film provided on said cladding layer to serve as a light emission layer, and a second semiconductive cladding layer of a second conductivity type provided on the active layer to define a light waveguide channel of the laser. The second cladding layer is made of a compound semiconductor containing indium, phosphorus, and aluminum. A contact layer section is provided on the second cladding layer to cover the light waveguide channel.
    Type: Grant
    Filed: December 5, 1988
    Date of Patent: August 14, 1990
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasuo Ohba, Niyoko Watanabe, Hideto Sugawara, Masayuki Ishikawa, Yukio Watanabe, Motoyuki Yamamoto