Patents by Inventor Hatsumi Kawata

Hatsumi Kawata 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).

  • Transverse-mode stabilized semiconductor laser diode with slab-coupled waveguide
    Patent number: 4799228
    Abstract: A semiconductor laser diode includes two semiconductive cladding layers of different conductivity types, which are stacked on a substrate. An active layer of an undoped semiconductor film is sandwiched between the cladding layers. A channel groove is formed in a current blocking layer and the underlying cladding layer, to be deep enough to cause the current blocking layer to be divided into two parts. A waveguide layer covers the channel groove and the current-blocking layer, to provide a slab-coupled waveguide structure for transverse mode oscillation. The second cladding layer, the current-blocking layer, and the waveguide layer are composed of gallium arsenide containing aluminum.
    Type: Grant
    Filed: August 21, 1986
    Date of Patent: January 17, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroko Nagasaka, Gen-ichi Hatakoshi, Naohiro Shimada, Motoyuki Yamamoto, Masaki Okajima, Yoshio Iizuka, Hatsumi Kawata, Hideaki Kinoshita, Nobuyuki Matsuura