Patents by Inventor Katsutoshi Kohmoto

Katsutoshi Kohmoto 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).

  • Patent number: 6690852
    Abstract: In the manufacture of an arrayed waveguide grating type optical multiplexer/demultiplexer, respective slab waveguides are provided at input sides and output sides of a waveguide array in a cladding layer formed upon a substrate, which includes plural waveguides whose lengths differ and which are arranged in parallel; and an input waveguide is provided at the input side of the input side slab waveguide, while plural output waveguides are provided at the output side of the output side slab waveguide. The waveguides are made from a material for which the difference between the effective refractive indices for the two polarizations is large, and thereby, when multiplexed light which consists of plural lights of different wavelengths is inputted to said input waveguide, lights which have been separated by wavelength and by polarization are outputted from each of said output waveguides. As a result, it is possible to make a polarization/wavelength multiplex transmission circuit using fewer elements.
    Type: Grant
    Filed: June 20, 2001
    Date of Patent: February 10, 2004
    Assignee: Fujikura Ltd.
    Inventors: Hirokuni Ogawa, Katsutoshi Kohmoto, Kouji Ohura, Kenichiro Asano, Hideyuki Hosoya
  • Publication number: 20020021863
    Abstract: In the manufacture of an arrayed waveguide grating type optical multiplexer/demultiplexer, respective slab waveguides are provided at input sides and output sides of a waveguide array in a cladding layer formed upon a substrate, which includes plural waveguides whose lengths differ and which are arranged in parallel; and an input waveguide is provided at the input side of the input side slab waveguide, while plural output waveguides are provided at the output side of the output side slab waveguide. The waveguides are made from a material for which the difference between the effective refractive indices for the two polarizations is large, and thereby, when multiplexed light which consists of plural lights of different wavelengths is inputted to said input waveguide, lights which have been separated by wavelength and by polarization are outputted from each of said output waveguides. As a result, it is possible to make a polarization/wavelength multiplex transmission circuit using fewer elements.
    Type: Application
    Filed: June 20, 2001
    Publication date: February 21, 2002
    Inventors: Hirokuni Ogawa, Katsutoshi Kohmoto, Kouji Ohura, Kenichiro Asano, Hideyuki Hosoya