Patents by Inventor Ryohei Takei

Ryohei Takei 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: 9829726
    Abstract: An electro-optical modulator includes a substrate 201; an optical waveguide formed of a silicon-containing i-type amorphous semiconductor 204 on the substrate; and a silicon-containing p-type semiconductor layer 203 and a silicon-containing n-type semiconductor layer 205 arranged apart from each other with the silicon-containing optical waveguide formed of an i-type amorphous semiconductor 204 interposed therebetween and constituting optical waveguides together with the silicon-containing optical waveguide formed of an i-type amorphous semiconductor. The silicon-containing p-type semiconductor layer 203 and/or silicon-containing n-type semiconductor layer 205 area crystalline semiconductor layer.
    Type: Grant
    Filed: February 20, 2014
    Date of Patent: November 28, 2017
    Assignees: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATION
    Inventors: Toshihiro Kamei, Ryohei Takei, Masahiko Mori, Youichi Sakakibara, Junichi Fujikata
  • Patent number: 9690122
    Abstract: An optical semiconductor device in which a first optical waveguide 407 comprising a silicon-containing amorphous semiconductor layer and a second optical waveguide 409 containing a silicon-containing i-type semiconductor layer as a constituent element are disposed in different layers in a range in which optical interaction can occur. An electro-optical modulator 409 having a pin junction structure comprising a p-type semiconductor layer 403, an i-type semiconductor layer 404, and an n-type semiconductor layer 405 is provided to at least a portion of the second optical waveguide 409, and the index of refraction of the second optical waveguide is varied by the electro-optical modulator, whereby light waves propagated through the first optical waveguide are modulated.
    Type: Grant
    Filed: February 28, 2014
    Date of Patent: June 27, 2017
    Assignee: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Toshihiro Kamei, Ryohei Takei, Masahiko Mori, Youichi Sakakibara, Makoto Okano
  • Publication number: 20160357035
    Abstract: An optical semiconductor device in which a first optical waveguide 407 comprising a silicon-containing amorphous semiconductor layer and a second optical waveguide 409 containing a silicon-containing i-type semiconductor layer as a constituent element are disposed in different layers in a range in which optical interaction can occur. An electro-optical modulator 409 having a pin junction structure comprising a p-type semiconductor layer 403, an i-type semiconductor layer 404, and an n-type semiconductor layer 405 is provided to at least a portion of the second optical waveguide 409, and the index of refraction of the second optical waveguide is varied by the electro-optical modulator, whereby light waves propagated through the first optical waveguide are modulated.
    Type: Application
    Filed: February 28, 2014
    Publication date: December 8, 2016
    Inventors: Toshihiro Kamei, Ryohei Takei, Masahiko Mori, Youichi Sakakibara, Makoto Okano
  • Publication number: 20160349545
    Abstract: An object of the present invention is to provide an electro-optical modulator that allows high-speed carrier injection into a silicon-containing i-type amorphous semiconductor, particularly a-Si:H, and has little optical loss. An electro-optical modulator comprises: a substrate 201; an optical waveguide comprising a silicon-containing i-type amorphous semiconductor 204 formed on the substrate; and a silicon-containing p-type semiconductor layer 203 and a silicon-containing n-type semiconductor layer 205 arranged apart from each other with the silicon-containing optical waveguide comprising an i-type amorphous semiconductor 204 interposed therebetween and constituting optical waveguides together with the silicon-containing optical waveguide comprising an i-type amorphous semiconductor. The silicon-containing p-type semiconductor layer 203 and/or silicon-containing n-type semiconductor layer 205 are a crystalline semiconductor layer.
    Type: Application
    Filed: February 20, 2014
    Publication date: December 1, 2016
    Applicants: National Institute of Advanced Industrial Science and Technology, Photonics Electronics Technology Research Association
    Inventors: Toshihiro Kamei, Ryohei Takei, Masahiko Mori, Youichi Sakakibara, Junichi Fujikata
  • Patent number: 9435946
    Abstract: An interlayer light wave coupling device includes a substrate; a first core disposed on the substrate and having a first acute structure; a third core spatially set apart from the first core and having a second acute structure; and a second core disposed between the first core and the third core and having a smaller index of refraction than the first core and the third core. The acute structures of the first core and the third core are disposed so as to have no overlap as viewed from above.
    Type: Grant
    Filed: October 4, 2013
    Date of Patent: September 6, 2016
    Assignee: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Youichi Sakakibara, Ryohei Takei, Masahiko Mori, Toshihiro Kamei
  • Publication number: 20160139334
    Abstract: An interlayer light wave coupling device includes a substrate; a first core disposed on the substrate and having a first acute structure; a third core spatially set apart from the first core and having a second acute structure; and a second core disposed between the first core and the third core and having a smaller index of refraction than the first core and the third core. The acute structures of the first core and the third core are disposed so as to have no overlap as viewed from above.
    Type: Application
    Filed: October 4, 2013
    Publication date: May 19, 2016
    Applicant: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Youichi Sakakibara, Ryohei Takei, Masahiko Mori, Toshihiro Kamei
  • Patent number: 8965157
    Abstract: A semiconductor pointed structure formed at an end portion of the core structure of a semiconductor photonic wire waveguide has a sloped side wall on at least one of the sides that constitute the pointed structure. The semiconductor pointed structure decreases in width and thickness towards the distal end. A method for fabrication of the structure is also disclosed.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: February 24, 2015
    Assignee: National Institute of Advanced Industrial Science and Technology
    Inventors: Youichi Sakakibara, Ryohei Takei, Masahiko Mori, Toshihiro Kamei