Patents by Inventor Sunil Kumar Singh Khatana

Sunil Kumar Singh Khatana 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: 9002215
    Abstract: A coherent optical receiver measures a portion of a spectra of a multi-channel optical signal that includes at least one signal adjacent to a selected signal. The coherent optical receiver determines structure and bandwidth information for the measured portion of spectra, and determines one or more filter parameters for the selected signal based on the structure and bandwidth information of the at least one signal adjacent to the selected signal. The coherent optical receiver adjusts one or more active filter parameters of a carrier phase estimator in the optical coherent receiver to have values corresponding to the determined one or more filter parameters.
    Type: Grant
    Filed: July 11, 2013
    Date of Patent: April 7, 2015
    Assignee: Oclaro, Inc.
    Inventor: Sunil Kumar Singh Khatana
  • Patent number: 8768178
    Abstract: Feed-forward and feedback strategies are used to control local oscillator power and transimpedance amplifier gain in a high-speed coherent optical receiver.
    Type: Grant
    Filed: September 15, 2011
    Date of Patent: July 1, 2014
    Assignee: Opnext Subsystems, Inc.
    Inventors: Sunil Kumar Singh Khatana, George Zarris
  • Patent number: 8644420
    Abstract: I/Q data skew in a QPSK modulator may be detected by sending identical or complementary data streams to I and Q channel PSK modulators, setting the relative carrier phase between I and Q to zero or ?, and monitoring the average QPSK output power, where the data streams sent to the I and Q channels include streams of alternating ones and zeroes.
    Type: Grant
    Filed: April 1, 2011
    Date of Patent: February 4, 2014
    Assignee: Opnext Subsystems, Inc.
    Inventors: Sunil Kumar Singh Khatana, Lee Dardis
  • Patent number: 8634726
    Abstract: Digital timing error detection systems and techniques are described. The described techniques are independent of polarization and differential-group-delay and are used to perform timing recovery of polarization-multiplexed coherent optical systems.
    Type: Grant
    Filed: May 14, 2012
    Date of Patent: January 21, 2014
    Assignee: Opnext Subsystems, Inc.
    Inventors: Bo Zhang, Sunil Kumar Singh Khatana
  • Publication number: 20140016927
    Abstract: A coherent optical receiver measures a portion of a spectra of a multi-channel optical signal that includes at least one signal adjacent to a selected signal. The coherent optical receiver determines structure and bandwidth information for the measured portion of spectra, and determines one or more filter parameters for the selected signal based on the structure and bandwidth information of the at least one signal adjacent to the selected signal. The coherent optical receiver adjusts one or more active filter parameters of a carrier phase estimator in the optical coherent receiver to have values corresponding to the determined one or more filter parameters.
    Type: Application
    Filed: July 11, 2013
    Publication date: January 16, 2014
    Inventor: Sunil Kumar Singh Khatana
  • Publication number: 20140016928
    Abstract: A method for extracting admin information from a modulated optical signal. A coherent optical receiver receives the modulated optical signal, where a nominal carrier frequency of the modulated optical signal was modulated using a first slow frequency and second slow frequency associated with an electronic admin signal. The receiver converts the modulated optical signal to an electronic signal, and estimates estimating a plurality of carrier phases of the electronic signal. The receiver determines a plurality of offset values by calculating the time derivative of at least some of the estimated carrier phases, wherein each of the plurality of offset values are proportional to an associated frequency offset component, and the frequency of each offset value corresponds to the first slow frequency or the second slow frequency. The receiver extracts information corresponding to the electronic admin signal using the determined plurality of offset values.
    Type: Application
    Filed: July 12, 2013
    Publication date: January 16, 2014
    Inventor: Sunil Kumar Singh Khatana
  • Publication number: 20140016172
    Abstract: A method for determining, by a modulator assembly, an optimal drive point for a Mach-Zehnder modulator (MZM). The modulator assembly applies an electrical modulation signal to the MZM to modulate an optical input signal and create a modulated optical output signal, the modulated optical output having a spectrum that includes a first and third harmonic. The modulator assembly measures the difference in magnitude between the first harmonic and the third harmonic as the amplitude of the electrical modulation signal is varied, and determines a value for the amplitude of the electrical modulation signal that corresponds to a maximum difference between the first harmonic and the third harmonic.
    Type: Application
    Filed: July 11, 2013
    Publication date: January 16, 2014
    Inventors: Sunil Kumar Singh Khatana, Lee Dardis
  • Patent number: 8565621
    Abstract: A method for detecting and measuring time skew in high-speed DP-QPSK coherent optical receivers is described.
    Type: Grant
    Filed: September 23, 2011
    Date of Patent: October 22, 2013
    Assignee: Opnext Subsystems, Inc.
    Inventors: Edem Ibragimov, Sunil Kumar Singh Khatana
  • Patent number: 8565271
    Abstract: Patterns detected by a low-speed receiver at the output of a high-speed multiplexer are used to determine when multiplexer input lanes are deskewed.
    Type: Grant
    Filed: April 1, 2011
    Date of Patent: October 22, 2013
    Assignee: Opnext Subsystems, Inc.
    Inventors: Sunil Kumar Singh Khatana, Hong Jiang
  • Publication number: 20130170829
    Abstract: Coherent optical receiver performance is optimized and made adaptable to changing optical channel conditions by providing feedback loops to adjust receiver parameters based on measured receiver performance.
    Type: Application
    Filed: December 30, 2011
    Publication date: July 4, 2013
    Applicant: OPNEXT SUBSYSTEMS, INC.
    Inventor: Sunil Kumar Singh Khatana
  • Patent number: 8428183
    Abstract: I/Q data skew in a QPSK modulator may be detected by sending identical or complementary data streams to I and Q channel PSK modulators, setting the relative carrier phase between I and Q to zero or ?, and monitoring the average QPSK output power, where the data streams sent to the I and Q channels include pseudorandom streams of ones and zeroes.
    Type: Grant
    Filed: April 1, 2011
    Date of Patent: April 23, 2013
    Assignee: Opnext Subsystems, Inc.
    Inventors: Sunil Kumar Singh Khatana, Edem Ibragimov
  • Publication number: 20130071109
    Abstract: Feed-forward and feedback strategies are used to control local oscillator power and transimpedance amplifier gain in a high-speed coherent optical receiver.
    Type: Application
    Filed: September 15, 2011
    Publication date: March 21, 2013
    Applicant: OPNEXT SUBSYSTEMS, INC.
    Inventors: Sunil Kumar Singh Khatana, George Zarris
  • Publication number: 20120288275
    Abstract: Digital timing error detection systems and techniques are described. The described techniques are independent of polarization and differential-group-delay and are used to perform timing recovery of polarization-multiplexed coherent optical systems.
    Type: Application
    Filed: May 14, 2012
    Publication date: November 15, 2012
    Applicant: OPNEXT SUBSYSTEMS, INC.
    Inventors: Bo Zhang, Sunil Kumar Singh Khatana
  • Publication number: 20120250793
    Abstract: I/Q data skew in a QPSK modulator may be detected by sending identical or complementary data streams to I and Q channel PSK modulators, setting the relative carrier phase between I and Q to zero or ?, and monitoring the average QPSK output power, where the data streams sent to the I and Q channels include pseudorandom streams of ones and zeroes.
    Type: Application
    Filed: April 1, 2011
    Publication date: October 4, 2012
    Applicant: OPNEXT SUBSYSTEMS, INC.
    Inventors: Sunil Kumar Singh Khatana, Edem Ibragimov
  • Publication number: 20120251099
    Abstract: Patterns detected by a low-speed receiver at the output of a high-speed multiplexer are used to determine when multiplexer input lanes are deskewed.
    Type: Application
    Filed: April 1, 2011
    Publication date: October 4, 2012
    Applicant: OPNEXT SUBSYSTEMS, INC.
    Inventors: Sunil Kumar Singh Khatana, Hong Jiang
  • Publication number: 20120250792
    Abstract: I/Q data skew in a QPSK modulator may be detected by sending identical or complementary data streams to I and Q channel PSK modulators, setting the relative carrier phase between I and Q to zero or ?, and monitoring the average QPSK output power, where the data streams sent to the I and Q channels include streams of alternating ones and zeroes.
    Type: Application
    Filed: April 1, 2011
    Publication date: October 4, 2012
    Applicant: OPNEXT SUBSYSTEMS, INC.
    Inventors: Sunil Kumar Singh Khatana, Lee Dardis
  • Publication number: 20120224847
    Abstract: A method for detecting and measuring time skew in high-speed DP-QPSK coherent optical receivers is described.
    Type: Application
    Filed: September 23, 2011
    Publication date: September 6, 2012
    Applicant: OPNEXT SUBSYSTEMS, INC.
    Inventors: Edem Ibragimov, Sunil Kumar Singh Khatana