Patents by Inventor Koichi Matsumi

Koichi Matsumi 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).

  • Faraday rotator for an optical device
    Patent number: 4522473
    Abstract: A Faraday rotator has a non-magnetic garnet substrate with a ferrimagnetic garnet film epitaxially grown on the substrate. A magnet induces a magnetic field in the film for rotating the plane of polarization of a light-beam which strikes an end surface of the film at a predetermined angle. The substrate and film are composed of a material wherein the difference (.DELTA. a=a.sub.s -a.sub.f) between the lattice constant a.sub.s of the substrate and the lattice constant a.sub.f of the film satisfies .vertline..DELTA.a.vertline..ltoreq. 0.001A (angstrom).
    Type: Grant
    Filed: March 22, 1982
    Date of Patent: June 11, 1985
    Assignee: Nippon Electric Co., Ltd.
    Inventors: Taketoshi Hibiya, Yoshinori Ohta, Koichi Matsumi