Patents by Inventor Xiaoguang TU

Xiaoguang TU 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: 11002913
    Abstract: An optical dispersion compensator integrated with a silicon photonics system including a first phase-shifter coupled to a second phase-shifter in parallel on the silicon substrate characterized in an athermal condition. The dispersion compensator further includes a third phase-shifter on the silicon substrate to the first phase-shifter and the second phase-shifter through two 2×2 splitters to form an optical loop. A second entry port of a first 2×2 splitter is for coupling with an input fiber and a second exit port of a second 2×2 splitter is for coupling with an output fiber. The optical loop is characterized by a total phase delay tunable via each of the first phase-shifter, the second phase-shifter, and the third phase-shifter such that a normal dispersion (>0) at a certain wavelength in the input fiber is substantially compensated and independent of temperature.
    Type: Grant
    Filed: March 30, 2020
    Date of Patent: May 11, 2021
    Assignee: INPHI CORPORATION
    Inventors: Xiaoguang Tu, Radhakrishnan L. Nagarajan, Masaki Kato
  • Publication number: 20210116726
    Abstract: A silicon optical modulator is fabricated to have a multi-slab structure between the contacts and the waveguide, imparting desirable performance attributes. A first slab comprises dopant of a first level. A second slab adjacent to (e.g., on top of) the first slab, comprises a doped region proximate to a contact, and an intrinsic region proximate to the waveguide. The parallel resistance properties and low overlap between the highly doped silicon and optical mode pigtail afforded by the multi-slab configuration, allow the modulator to operate with reduced optical losses and at a high speed. Embodiments may be implemented in a Mach-Zehnder interferometer or in micro-ring resonator modulator configuration.
    Type: Application
    Filed: November 10, 2020
    Publication date: April 22, 2021
    Inventors: Xiaoguang TU, Masaki KATO
  • Patent number: 10852570
    Abstract: A silicon optical modulator is fabricated to have a multi-slab structure between the contacts and the waveguide, imparting desirable performance attributes. A first slab comprises dopant of a first level. A second slab adjacent to (e.g., on top of) the first slab, comprises a doped region proximate to a contact, and an intrinsic region proximate to the waveguide. The parallel resistance properties and low overlap between the highly doped silicon and optical mode pigtail afforded by the multi-slab configuration, allow the modulator to operate with reduced optical losses and at a high speed. Embodiments may be implemented in a Mach-Zehnder interferometer or in micro-ring resonator modulator configuration.
    Type: Grant
    Filed: October 16, 2019
    Date of Patent: December 1, 2020
    Assignee: INPHI CORPORATION
    Inventors: Xiaoguang Tu, Masaki Kato
  • Publication number: 20200257050
    Abstract: An optical dispersion compensator integrated with a silicon photonics system including a first phase-shifter coupled to a second phase-shifter in parallel on the silicon substrate characterized in an athermal condition. The dispersion compensator further includes a third phase-shifter on the silicon substrate to the first phase-shifter and the second phase-shifter through two 2×2 splitters to form an optical loop. A second entry port of a first 2×2 splitter is for coupling with an input fiber and a second exit port of a second 2×2 splitter is for coupling with an output fiber. The optical loop is characterized by a total phase delay tunable via each of the first phase-shifter, the second phase-shifter, and the third phase-shifter such that a normal dispersion (>0) at a certain wavelength in the input fiber is substantially compensated and independent of temperature.
    Type: Application
    Filed: March 30, 2020
    Publication date: August 13, 2020
    Inventors: Xiaoguang TU, Radhakrishnan L. NAGARAJAN, Masaki KATO
  • Patent number: 10641965
    Abstract: An optical dispersion compensator integrated with a silicon photonics system including a first phase-shifter coupled to a second phase-shifter in parallel on the silicon substrate characterized in an athermal condition. The dispersion compensator further includes a third phase-shifter on the silicon substrate to the first phase-shifter and the second phase-shifter through two 2×2 splitters to form an optical loop. A second entry port of a first 2×2 splitter is for coupling with an input fiber and a second exit port of a second 2×2 splitter is for coupling with an output fiber. The optical loop is characterized by a total phase delay tunable via each of the first phase-shifter, the second phase-shifter, and the third phase-shifter such that a normal dispersion (>0) at a certain wavelength in the input fiber is substantially compensated and independent of temperature.
    Type: Grant
    Filed: December 9, 2019
    Date of Patent: May 5, 2020
    Assignee: INPHI CORPORATION
    Inventors: Xiaoguang Tu, Radhakrishnan L. Nagarajan, Masaki Kato
  • Publication number: 20200110220
    Abstract: An optical dispersion compensator integrated with a silicon photonics system including a first phase-shifter coupled to a second phase-shifter in parallel on the silicon substrate characterized in an athermal condition. The dispersion compensator further includes a third phase-shifter on the silicon substrate to the first phase-shifter and the second phase-shifter through two 2×2 splitters to form an optical loop. A second entry port of a first 2×2 splitter is for coupling with an input fiber and a second exit port of a second 2×2 splitter is for coupling with an output fiber. The optical loop is characterized by a total phase delay tunable via each of the first phase-shifter, the second phase-shifter, and the third phase-shifter such that a normal dispersion (>0) at a certain wavelength in the input fiber is substantially compensated and independent of temperature.
    Type: Application
    Filed: December 9, 2019
    Publication date: April 9, 2020
    Inventors: Xiaoguang TU, Radhakrishnan L. NAGARAJAN, Masaki KATO
  • Patent number: 10527795
    Abstract: An optical dispersion compensator integrated with a silicon photonics system including a first phase-shifter coupled to a second phase-shifter in parallel on the silicon substrate characterized in an athermal condition. The dispersion compensator further includes a third phase-shifter on the silicon substrate to the first phase-shifter and the second phase-shifter through two 2×2 splitters to form an optical loop. A second entry port of a first 2×2 splitter is for coupling with an input fiber and a second exit port of a second 2×2 splitter is for coupling with an output fiber. The optical loop is characterized by a total phase delay tunable via each of the first phase-shifter, the second phase-shifter, and the third phase-shifter such that a normal dispersion (>0) at a certain wavelength in the input fiber is substantially compensated and independent of temperature.
    Type: Grant
    Filed: October 11, 2018
    Date of Patent: January 7, 2020
    Assignee: INPHI CORPORATION
    Inventors: Xiaoguang Tu, Radhakrishnan L. Nagarajan, Masaki Kato
  • Publication number: 20190041580
    Abstract: An optical dispersion compensator integrated with a silicon photonics system including a first phase-shifter coupled to a second phase-shifter in parallel on the silicon substrate characterized in an athermal condition. The dispersion compensator further includes a third phase-shifter on the silicon substrate to the first phase-shifter and the second phase-shifter through two 2×2 splitters to form an optical loop. A second entry port of a first 2×2 splitter is for coupling with an input fiber and a second exit port of a second 2×2 splitter is for coupling with an output fiber. The optical loop is characterized by a total phase delay tunable via each of the first phase-shifter, the second phase-shifter, and the third phase-shifter such that a normal dispersion (>0) at a certain wavelength in the input fiber is substantially compensated and independent of temperature.
    Type: Application
    Filed: October 11, 2018
    Publication date: February 7, 2019
    Inventors: Xiaoguang TU, Radhakrishnan L. NAGARAJAN, Masaki KATO
  • Patent number: 10126629
    Abstract: An optical dispersion compensator integrated with a silicon photonics system including a first phase-shifter coupled to a second phase-shifter in parallel on the silicon substrate characterized in an athermal condition. The dispersion compensator further includes a third phase-shifter on the silicon substrate to the first phase-shifter and the second phase-shifter through two 2×2 splitters to form an optical loop. A second entry port of a first 2×2 splitter is for coupling with an input fiber and a second exit port of a second 2×2 splitter is for coupling with an output fiber. The optical loop is characterized by a total phase delay tunable via each of the first phase-shifter, the second phase-shifter, and the third phase-shifter such that a normal dispersion (>0) at a certain wavelength in the input fiber is substantially compensated and independent of temperature.
    Type: Grant
    Filed: August 3, 2017
    Date of Patent: November 13, 2018
    Assignee: INPHI CORPORATION
    Inventors: Xiaoguang Tu, Radhakrishnan L. Nagarajan, Masaki Kato
  • Patent number: 9880404
    Abstract: An optical waveguide device includes a substrate; a lower cladding disposed on the substrate; a rib waveguide including a slab disposed on the lower cladding and a single rib disposed on the slab contiguous to the slab; and an upper cladding disposed on the rib waveguide. The rib waveguide includes a first doped region having a first electric conductivity exhibiting a P-type electric conductivity across the rib and the slab and a second doped region being contiguous to the first doped region and having a second electric conductivity exhibiting an N-type electric conductivity across the rib and the slab.
    Type: Grant
    Filed: October 4, 2016
    Date of Patent: January 30, 2018
    Assignees: FUJIKURA LTD., AGENCY FOR SCIENCE, TECHNOLOGY AND RESEARCH
    Inventors: Kensuke Ogawa, Kazuhiro Goi, Guo-Qiang Lo, Tsung-Yang Jason Liow, Xiaoguang Tu
  • Patent number: 9581545
    Abstract: An optical sensing system may include a light separation element configured to separate an input light into a plurality of sliced lights and a first resonator configured to receive one sliced light of the plurality of sliced lights. An effective refractive index of the first resonator may be changeable in response to a change in a refractive index of a cladding of the first resonator, a second resonator coupled to the first resonator and a detector configured to measure an intensity of the sliced light, the intensity of the sliced light based on a difference between a resonant wavelength of the first resonator and a resonant wavelength of the second resonator. The difference between a resonant wavelength of the first resonator and a resonant wavelength of the second resonator may be based on the effective refractive index of the first resonator.
    Type: Grant
    Filed: October 8, 2013
    Date of Patent: February 28, 2017
    Assignee: Agency for Science, Technology and Research
    Inventors: Junfeng Song, Xianshu Luo, Xiaoguang Tu, Qing Fang, Guo-Qiang Patrick Lo, Mingbin Yu
  • Publication number: 20170023810
    Abstract: An optical waveguide device includes a substrate; a lower cladding disposed on the substrate; a rib waveguide including a slab disposed on the lower cladding and a single rib disposed on the slab contiguous to the slab; and an upper cladding disposed on the rib waveguide. The rib waveguide includes a first doped region having a first electric conductivity exhibiting a P-type electric conductivity across the rib and the slab and a second doped region being contiguous to the first doped region and having a second electric conductivity exhibiting an N-type electric conductivity across the rib and the slab.
    Type: Application
    Filed: October 4, 2016
    Publication date: January 26, 2017
    Applicants: FUJIKURA LTD., AGENCY FOR SCIENCE, TECHNOLOGY AND RESEARCH
    Inventors: Kensuke OGAWA, Kazuhiro GOI, Guo-Qiang LO, Tsung-Yang Jason LIOW, Xiaoguang TU
  • Patent number: 9335263
    Abstract: An optical circuit for sensing a biological entity in a fluid and a method of configuring an optical circuit for sensing a biological entity in a fluid are provided. The optical circuit includes a sensing arrangement including a reference arm having a reference waveguide and a sensing arm having a waveguide; wherein lengths of the reference waveguide and the waveguide are configured in accordance with a temperature dependency reduction criterion.
    Type: Grant
    Filed: September 20, 2012
    Date of Patent: May 10, 2016
    Assignee: Agency for Science, Technology and Research
    Inventors: Xiaoguang Tu, Tsung-Yang Liow, Mingbin Yu, Guo-Qiang Lo
  • Patent number: 9329415
    Abstract: According to embodiments of the present invention, a method for forming an optical modulator is provided. The method includes providing a substrate, implanting dopants of a first conductivity type into the substrate to form a first doped region, implanting dopants of a second conductivity type into the substrate to form a second doped region, wherein a portion of the second doped region is formed over and overlaps with a portion of the first doped region to form a junction between the respective portions of the first doped region and the second doped region, and wherein a remaining portion of the second doped region is located outside of the junction, and forming a ridge waveguide, wherein the ridge waveguide overlaps with at least a part of the junction.
    Type: Grant
    Filed: November 5, 2013
    Date of Patent: May 3, 2016
    Assignee: Agency for Science, Technology and Research
    Inventors: Jun-Feng Song, Xianshu Luo, Xiaoguang Tu, Patrick Guo-Qiang Lo, Mingbin Yu
  • Publication number: 20150268161
    Abstract: An optical sensing system may include a light separation element configured to separate an input light into a plurality of sliced lights and a first resonator configured to receive one sliced light of the plurality of sliced lights. An effective refractive index of the first resonator may be changeable in response to a change in a refractive index of a cladding of the first resonator, a second resonator coupled to the first resonator and a detector configured to measure an intensity of the sliced light, the intensity of the sliced light based on a difference between a resonant wavelength of the first resonator and a resonant wavelength of the second resonator. The difference between a resonant wavelength of the first resonator and a resonant wavelength of the second resonator may be based on the effective refractive index of the first resonator.
    Type: Application
    Filed: October 8, 2013
    Publication date: September 24, 2015
    Inventors: Junfeng Song, Xianshu Luo, Xiaoguang Tu, Qing Fang, Guo-Qiang Patrick Lo, Mingbin Yu
  • Patent number: 9110314
    Abstract: According to embodiments of the present invention, an optical modulator is provided. The optical modulator includes a depletion region comprising a junction between from a first conductivity type portion and a second conductivity type portion, a first intrinsic region, and a second intrinsic region, and wherein the depletion region is disposed between the first intrinsic region and the second intrinsic region.
    Type: Grant
    Filed: December 28, 2011
    Date of Patent: August 18, 2015
    Assignee: Agency for Science, Technology and Research
    Inventors: Xiaoguang Tu, Tsung-Yang Jason Liow, Guo Qiang Patrick Lo
  • Publication number: 20140127842
    Abstract: According to embodiments of the present invention, a method for forming an optical modulator is provided. The method includes providing a substrate, implanting dopants of a first conductivity type into the substrate to form a first doped region, implanting dopants of a second conductivity type into the substrate to form a second doped region, wherein a portion of the second doped region is formed over and overlaps with a portion of the first doped region to form a junction between the respective portions of the first doped region and the second doped region, and wherein a remaining portion of the second doped region is located outside of the junction, and forming a ridge waveguide, wherein the ridge waveguide overlaps with at least a part of the junction.
    Type: Application
    Filed: November 5, 2013
    Publication date: May 8, 2014
    Applicant: Agency for Science, Technology and Research
    Inventors: Jun-Feng Song, Xianshu Luo, Xiaoguang Tu, Patrick Guo-Qiang Lo, Mingbin Yu
  • Publication number: 20120189239
    Abstract: According to embodiments of the present invention, an optical modulator is provided. The optical modulator includes a depletion region comprising a junction between from a first conductivity type portion and a second conductivity type portion, a first intrinsic region, and a second intrinsic region, and wherein the depletion region is disposed between the first intrinsic region and the second intrinsic region.
    Type: Application
    Filed: December 28, 2011
    Publication date: July 26, 2012
    Inventors: Xiaoguang TU, Tsung-Yang Jason Liow, Guo Qiang Patrick Lo