Patents by Inventor Tiangong Liu

Tiangong Liu 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: 10203454
    Abstract: A dense wavelength-division multiplexing (DWDM) optical network includes an optical input port configured to receive unmodulated optical signals from the optical fiber comprising wavelength channels; one or more modulators coupled to the optical input port wherein the one or more modulators are each configured to modulate a respective first wavelength channel of the wavelength channels with respective data to produce a modulated first wavelength channel when the modulator is in a transmit state; wherein an input optical power of each modulator is kept at substantially a first level and an output optical power of the each modulator is kept at substantially a second level during operation of the modulator. A method and an optical network node are also disclosed therein.
    Type: Grant
    Filed: May 31, 2017
    Date of Patent: February 12, 2019
    Assignee: Futurewei Technologies, Inc.
    Inventors: Tiangong Liu, Xiao Andy Shen, Qianfan Xu, Feng Zhang
  • Patent number: 10042190
    Abstract: A Dual Parallel (DP)-Inphase/Quadrature (I/Q) Mach-Zehnder Modulator (MZM) bias controller configured to generate a pair of orthogonal dither signals; multiply the pair of dither signals to create a second order orthogonal dither signal; and lock an Inphase (I) I MZM of a DP-I/Q MZM to a value of a corresponding I component of a transmission signal by applying the pair of orthogonal dither signal to a Quadrature (Q) MZM and a Phase (P) MZM of the DP-I/Q MZM; applying an I bias signal to the I MZM of the DP-I/Q MZM; detecting an output of the DP-I/Q MZM; and determining an I error signal in the output of the I MZM of the DP-I/Q MZM based on the product of second order dither signal and the output of the DP-I/Q MZM.
    Type: Grant
    Filed: June 10, 2016
    Date of Patent: August 7, 2018
    Assignee: Futurewei Technologies, Inc.
    Inventors: Tiangong Liu, Hongbing Lei, Xiao Shen
  • Publication number: 20170357110
    Abstract: A Dual Parallel (DP)-Inphase/Quadrature (I/Q) Mach-Zehnder Modulator (MZM) bias controller configured to generate a pair of orthogonal dither signals; multiply the pair of dither signals to create a second order orthogonal dither signal; and lock an Inphase (I) I MZM of a DP-I/Q MZM to a value of a corresponding I component of a transmission signal by applying the pair of orthogonal dither signal to a Quadrature (Q) MZM and a Phase (P) MZM of the DP-I/Q MZM; applying an I bias signal to the I MZM of the DP-I/Q MZM; detecting an output of the DP-I/Q MZM; and determining an I error signal in the output of the I MZM of the DP-I/Q MZM based on the product of second order dither signal and the output of the DP-I/Q MZM.
    Type: Application
    Filed: June 10, 2016
    Publication date: December 14, 2017
    Inventors: Tiangong Liu, Hongbing Lei, Xiao Shen
  • Publication number: 20170346592
    Abstract: A dense wavelength-division multiplexing (DWDM) optical network includes an optical input port configured to receive unmodulated optical signals from the optical fiber comprising wavelength channels; one or more modulators coupled to the optical input port wherein the one or more modulators are each configured to modulate a respective first wavelength channel of the wavelength channels with respective data to produce a modulated first wavelength channel when the modulator is in a transmit state; wherein an input optical power of each modulator is kept at substantially a first level and an output optical power of the each modulator is kept at substantially a second level during operation of the modulator. A method and an optical network node are also disclosed therein.
    Type: Application
    Filed: May 31, 2017
    Publication date: November 30, 2017
    Applicant: Futurewei Technologies, Inc.
    Inventors: Tiangong LIU, Xiao Andy SHEN
  • Patent number: 7460298
    Abstract: An apparatus is provided comprising a dual optical amplifier. The two optical amplifiers are integrated, in that they share at a set of optical, electrical, or opto-electrical components. The two optical amplifiers may share a pump laser. Alternatively, the optical amplifiers may share photo-detectors. Methods of controlling the signal strength of output signals are also provided. A chip-based integrated optical dual amplifier, using Erbium-Doped Waveguides, is also provided.
    Type: Grant
    Filed: January 30, 2003
    Date of Patent: December 2, 2008
    Assignee: Oplink Communications, Inc.
    Inventors: Jinghui Li, Genzao Zhang, Tongqing Wang, Tiangong Liu
  • Patent number: 7127174
    Abstract: A novel optical time division multiplexing (OTDM) module based on hybrid-integrated optical chips is disclosed. An integrated modulator chip generates optical RZ signal streams which are then interleaved in an integrated time-delay chip to produce an OTDM signal. The integrated modulator chip is coupled and secured to the integrated time-delay chip via a suitable optical index-matching layer or collimating lenses. Such an approach alleviates the stability problems offered by conventional fiber-based OTDM technology and aids in reducing the size and complexity as well as lowering the cost for the assembly. Furthermore, the time-delay chip of the present invention offers fine tuning capabilities thereby allowing for slight adjustments in the interleaving of optical signal streams when non-standard data transmission rates are required.
    Type: Grant
    Filed: November 16, 2001
    Date of Patent: October 24, 2006
    Assignee: Oplink Communications, Inc.
    Inventors: Tiangong Liu, Jinghui Li, Tongqing Wang
  • Patent number: 7039261
    Abstract: Systems and methods for providing compact dispersion compensation modules. In one implementation, a dispersion compensation module includes a polarizer having a first port, a second port, and a third port. The dispersion compensation module also includes a reflection etalon and a quarter-waveplate positioned between the reflection etalon and the second port of the polarizer.
    Type: Grant
    Filed: April 15, 2004
    Date of Patent: May 2, 2006
    Assignee: Oplink Communications, Inc.
    Inventors: Xiaoli Fu, Tongqing Wang, Jinghui Li, Tiangong Liu, Feng Shi, Genzao Zhang
  • Patent number: 6950972
    Abstract: A multi-purpose bit error rate tester (MPBERT) and a method of bit error rate (BER) testing of electrical and optical components and subsystems of electrical and optical communications systems is provided. The invention provides for bit error rate testing both in the optical and the electrical domain, and for bit error rate testing at higher than achievable rates in the electrical domain by multiplexing and demultiplexing in the optical domain. An MPBERT constructed according to the invention incorporates at least one optical multiplexer, and advantageously incorporates at least one optical demultiplexer, and in some embodiments uses high data rate optical RZ to NRZ conversion and high data rate optical NRZ to RZ conversion.
    Type: Grant
    Filed: November 16, 2001
    Date of Patent: September 27, 2005
    Assignee: Oplink Communications, Inc.
    Inventors: Tiangong Liu, Jinghui Li, Tongqing Wang
  • Patent number: 6865311
    Abstract: A Re-Configurable Dispersion Compensation Module is provided. A new approach to the variable DCM, the RDCM combines existing optical switch technology with existing fixed DCM technology and advantageously also with existing TDCM technology into a programmable smart optical component. Advantageously Micro-Electrical Mechanical Switch (MEMS) optical switch technology may be used. The alternate RDCM technology provides a controller, and a set of controllable switches to employ a set of DCMs and TDCMs for adjusting the dispersion compensation along an optical signal path. This alternate RDCM technology mitigates the problems of conventional TDCMs, while fitting most of the requirements for high speed systems, and being of a compact size.
    Type: Grant
    Filed: April 10, 2002
    Date of Patent: March 8, 2005
    Inventors: Jinghui Li, Tongqing Wang, Xiaoli Fu, Tiangong Liu, Genzao Zhang
  • Publication number: 20050036736
    Abstract: Systems and methods for providing compact dispersion compensation modules. In one implementation, a dispersion compensation module includes a polarizer having a first port, a second port, and a third port. The dispersion compensation module also includes a reflection etalon and a quarter-waveplate positioned between the reflection etalon and the second port of the polarizer.
    Type: Application
    Filed: April 15, 2004
    Publication date: February 17, 2005
    Inventors: Xiaoli Fu, Tongqing Wang, Jinghui Li, Tiangong Liu, Feng Shi, Genzao Zhang
  • Publication number: 20040212875
    Abstract: An apparatus is provided comprising a dual optical amplifier. The two optical amplifiers are integrated, in that they share at a set of optical, electrical, or opto-electrical components. The two optical amplifiers may share a pump laser. Alternatively, the optical amplifiers may share photo-detectors. Methods of controlling the signal strength of output signals are also provided. A chip-based integrated optical dual amplifier, using Erbium-Doped Waveguides, is also provided.
    Type: Application
    Filed: January 30, 2003
    Publication date: October 28, 2004
    Inventors: Jinghui Li, Genzao Zhang, Tongqing Wang, Tiangong Liu
  • Publication number: 20040208619
    Abstract: A Re-Configurable Dispersion Compensation Module is provided. A new approach to the variable DCM, the RDCM combines existing optical switch technology with existing fixed DCM technology and advantageously also with existing TDCM technology into a programmable smart optical component. Advantageously Micro-Electrical Mechanical Switch (MEMS) optical switch technology may be used. The alternate RDCM technology provides a controller, and a set of controllable switches to employ a set of DCMs and TDCMs for adjusting the dispersion compensation along an optical signal path. This alternate RDCM technology mitigates the problems of conventional TDCMs, while fitting most of the requirements for high speed systems, and being of a compact size.
    Type: Application
    Filed: April 10, 2002
    Publication date: October 21, 2004
    Inventors: Jinghui Li, Tongqing Wang, Xiaoli Fu, Tiangong Liu, Genzao Zhang
  • Publication number: 20030095311
    Abstract: A novel optical time division multiplexing (OTDM) module based on hybrid-integrated optical chips is disclosed. An integrated modulator chip generates optical RZ signal streams which are then interleaved in an integrated time-delay chip to produce an OTDM signal. The integrated modulator chip is coupled and secured to the integrated time-delay chip via a suitable optical index-matching layer or collimating lenses. Such an approach alleviates the stability problems offered by conventional fiber-based OTDM technology and aids in reducing the size and complexity as well as lowering the cost for the assembly. Furthermore, the time-delay chip of the present invention offers fine tuning capabilities thereby allowing for slight adjustments in the interleaving of optical signal streams when non-standard data transmission rates are required.
    Type: Application
    Filed: November 16, 2001
    Publication date: May 22, 2003
    Inventors: Tiangong Liu, Jinghui Li, Tongqing Wang
  • Publication number: 20030097622
    Abstract: A multi-purpose bit error rate tester (MPBERT) and a method of bit error rate (BER) testing of electrical and optical components and subsystems of electrical and optical communications systems is provided. The invention provides for bit error rate testing both in the optical and the electrical domain, and for bit error rate testing at higher than achievable rates in the electrical domain by multiplexing and demultiplexing in the optical domain. An MPBERT constructed according to the invention incorporates at least one optical multiplexer, and advantageously incorporates at least one optical demultiplexer, and in some embodiments uses high data rate optical RZ to NRZ conversion and high data rate optical NRZ to RZ conversion.
    Type: Application
    Filed: November 16, 2001
    Publication date: May 22, 2003
    Inventors: Tiangong Liu, Jinghui Li, Tongqing Wang