Patents by Inventor Tunetoshi Saito

Tunetoshi Saito 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: 6829418
    Abstract: An optical waveguide circuit device strong in impact strength in dropping, etc. is provided. A waveguide pattern is formed on a silicon substrate in this optical waveguide circuit device. For example, this waveguide pattern has an optical input waveguide, a first slab waveguide, an arrayed waveguide including a plurality of channel waveguides having lengths different from each other and arranged side by side, a second slab waveguide, and a plurality of optical output waveguides arranged side by side. The first slab waveguide is separated on a cross separating face crossing an optical path passing the first slab waveguide. A temperature dependence in light transmission central wavelength of an arrayed waveguide grating is reduced by sliding and moving a separating slab waveguide side by a slide moving member along the separating face depending on temperature.
    Type: Grant
    Filed: September 19, 2001
    Date of Patent: December 7, 2004
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Kazuhisa Kashihara, Yoshinobu Nekado, Kazutaka Nara, Tunetoshi Saito
  • Patent number: 6668116
    Abstract: An arrayed waveguide grating type optical multiplexer/demultiplexer of the invention eliminates the temperature dependency of the light transmission center wavelengths and suppresses an increase in insertion loss with a simple configuration even under the conditions of high temperature and high humidity. A waveguide forming area comprising an optical input waveguide, a first slab waveguide, an arrayed waveguide formed of a plurality of channel waveguides arranged side by side having a different length each other, and a plurality of optical output waveguides connected one by one is formed on a substrate. For example, the first slab waveguide is separated at crossed separation planes that cross the path of light passing through the first slab waveguide. On the crossed separation planes, a matching grease is applied. A thin film member for covering the area arranged with the matching grease is disposed to suppress the evaporation of the matching grease.
    Type: Grant
    Filed: July 16, 2001
    Date of Patent: December 23, 2003
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Kazuhisa Kashihara, Kazutaka Nara, Yoshinobu Nekado, Tunetoshi Saito
  • Patent number: 6591044
    Abstract: An optical waveguide circuit module of the invention is a highly reliable optical waveguide circuit module where cracks are not generated in an optical waveguide circuit chip housed even under a high temperature and high humidity environment. An optical waveguide circuit chip (25) comprises a waveguide forming region (10) formed on a substrate (1). The waveguide forming region (10) has a waveguide configuration sequentially connecting optical input waveguides (2), a first slab waveguide (3), an arrayed waveguide (4) made of a plurality of channel waveguides (4a) arranged side by side, the channel waveguides having a different length each other, a second slab waveguide (5), and a plurality of optical output waveguides (6) arranged side by side.
    Type: Grant
    Filed: September 25, 2001
    Date of Patent: July 8, 2003
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Kazuhisa Kashihara, Kazutaka Nara, Tunetoshi Saito, Takeshi Nakajima
  • Publication number: 20020064346
    Abstract: An optical waveguide circuit module of the invention is a highly reliable optical waveguide circuit module where cracks are not generated in an optical waveguide circuit chip housed even under a high temperature and high humidity environment. An optical waveguide circuit chip (25) comprises a waveguide forming region (10) formed on a substrate (1). The waveguide forming region (10) has a waveguide configuration sequentially connecting optical input waveguides (2), a first slab waveguide (3), an arrayed waveguide (4) made of a plurality of channel waveguides (4a) arranged side by side, the channel waveguides having a different length each other, a second slab waveguide (5), and a plurality of optical output waveguides (6) arranged side by side. Amounts of B2O3 and P2O5 to be doped in an over cladding of the waveguide forming region (10) are set greater to define a value of birefringence generated in the waveguide forming region (10).
    Type: Application
    Filed: September 25, 2001
    Publication date: May 30, 2002
    Applicant: THE FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kazuhisa Kashihara, Kazutaka Nara, Tunetoshi Saito, Takeshi Nakajima
  • Publication number: 20020034361
    Abstract: An optical waveguide circuit device strong in impact strength in dropping, etc. is provided. A waveguide pattern is formed on a silicon substrate in this optical waveguide circuit device. For example, this waveguide pattern has an optical input waveguide, a first slab waveguide, an arrayed waveguide including a plurality of channel waveguides having lengths different from each other and arranged side by side, a second slab waveguide, and a plurality of optical output waveguides arranged side by side. The first slab waveguide is separated on a cross separating face crossing an optical path passing the first slab waveguide. A temperature dependence in light transmission central wavelength of an arrayed waveguide grating is reduced by sliding and moving a separating slab waveguide side by a slide moving member along the separating face depending on temperature.
    Type: Application
    Filed: September 19, 2001
    Publication date: March 21, 2002
    Applicant: THE FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kazuhisa Kashihara, Yoshinobu Nekado, Kazutaka Nara, Tunetoshi Saito
  • Publication number: 20020025116
    Abstract: An arrayed waveguide grating type optical multiplexer/demultiplexer of the invention eliminates the temperature dependency of the light transmission center wavelengths and suppresses an increase in insertion loss with a simple configuration even under the conditions of high temperature and high humidity. A waveguide forming area comprising an optical input waveguide, a first slab waveguide, an arrayed waveguide formed of a plurality of channel waveguides arranged side by side having a different length each other, and a plurality of optical output waveguides connected one by one is formed on a substrate. For example, the first slab waveguide is separated at crossed separation planes that cross the path of light passing through the first slab waveguide. On the crossed separation planes, a matching grease is applied. A thin film member for covering the area arranged with the matching grease is disposed to suppress the evaporation of the matching grease.
    Type: Application
    Filed: July 16, 2001
    Publication date: February 28, 2002
    Applicant: THE FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kazuhisa Kashihara, Kazutaka Nara, Yoshinobu Nekado, Tunetoshi Saito