Patents by Inventor Toshiumi Kominato

Toshiumi Kominato 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).

  • Array waveguide diffraction grating type optical multiplexer/demultiplexer
    Patent number: 6904204
    Abstract: An object of this invention is to cancel a polarization dependence of a transmission center wavelength due to the waveguide birefringence in an array waveguide and a slab waveguide in an array waveguide diffraction grating type optical multiplexer/demultiplexer filter applied for optical communication, particularly, wavelength split multiplexing system. In order to achieve the object of this invention, a polarization mode convertor converts the TE mode in a waveguide to the TM mode and the TM mode to the TE mode. This conversion function makes it possible to cancel the polarization dependence of the transmission center wavelength due to the waveguide birefringence in the array waveguide and the slab waveguide in front of and behind the polarization mode convertor.
    Type: Grant
    Filed: October 9, 2002
    Date of Patent: June 7, 2005
    Assignees: NTT Electronics Corporation, Nippon Telegraph and Telephone
    Inventors: Yasuhiro Hida, Yasuyuki Inoue, Toshiumi Kominato
  • Array waveguide diffraction grating type optical multiplexer/branching filter
    Publication number: 20040247243
    Abstract: An object of this invention is to cancel a polarization dependence of a transmission center wavelength due to the waveguide birefringence in an array waveguide and a slab waveguide in an array waveguide diffraction grating type optical multiplexer/demultiplexer filter applied for optical communication, particularly, wavelength split multiplexing system. In order to achieve the object of this invention, a polarization mode convertor converts the TE mode in a waveguide to the TM mode and the TM mode to the TE mode. This conversion function makes it possible to cancel the polarization dependence of the transmission center wavelength due to the waveguide birefringence in the array waveguide and the slab waveguide in front of and behind the polarization mode convertor.
    Type: Application
    Filed: April 1, 2004
    Publication date: December 9, 2004
    Inventors: Yasuhiro Hida, Yasuyuki Inoue, Toshiumi Kominato