Patents by Inventor Lianshan Yan

Lianshan Yan 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).

  • Variable polarization-dependent-loss source
    Patent number: 6975454
    Abstract: An optical device including a beam splitter, polarization controller, and beam combiner is described. In some embodiments, the beam splitter and beam combiner are provided in a single element. An incoming light beam is split into two beams with different polarization components. The polarization of one or both of the beams is rotated using one or two polarization controllers such as fiber squeezers. The beams are then combined, so that a portion of each of the beams is provided to an output. The polarization dependent loss of the device can then be controlled by controlling the polarization rotation. In some embodiments, the rotation is dynamically controlled.
    Type: Grant
    Filed: July 31, 2002
    Date of Patent: December 13, 2005
    Assignee: General Photonics Corporation
    Inventors: Lianshan Yan, X. Steve Yao
  • Tunable pulse width generation of return-to-zero format for system optimization
    Publication number: 20040114857
    Abstract: A method for tunable optical pulse width generation comprises varying chirp of the signal of the pulse and concurrently varying dispersion of the signal. A system for tunable pulse width generation comprises a phase modulator providing the chirp modulation by modulating peak to peak phase of an optical signal and a tunable dispersion element providing the chromatic dispersion to the optical signal. A system for tunable pulse width return to zero optical signal transmission comprises at least one optical signal, a plurality of amplitude modulators for modulating the signal and a tunable pulse width generator comprising a phase modulator providing the chirp modulation and a tunable dispersion element providing the dispersion.
    Type: Application
    Filed: March 19, 2003
    Publication date: June 17, 2004
    Inventors: Lianshan Yan, Reza Motaghian Nezam, Alan E. Willner
  • Compensation and control of both first-order and higher-order polarization-mode dispersion
    Patent number: 6654103
    Abstract: Techniques and devices for controlling or compensating for both the first-order and high-order PMD effects in an optical signal by processing the signal in a fixed DGD stage and a variable DGD stage in sequence.
    Type: Grant
    Filed: September 4, 2001
    Date of Patent: November 25, 2003
    Assignee: University of Southern California
    Inventors: Qian Yu, Lianshan Yan, Sanggeon Lee, Alan E. Willner
  • Monitoring optical dispersion based on vestigial side band optical filtering
    Publication number: 20030123884
    Abstract: Techniques for monitoring frequency-dependent parameter and optical property such as optical dispersion in a modulated optical signal with sidebands based on optical vestigial sideband filtering. Monitoring implementations for both chromatic dispersion and polarization-mode dispersion are described as examples.
    Type: Application
    Filed: July 8, 2002
    Publication date: July 3, 2003
    Inventors: Alan E. Willner, Qian Yu, Zhongqi Pan, Lianshan Yan
  • Compensation and control of both first-order and higher-order polarization-mode dispersion
    Publication number: 20020075477
    Abstract: Techniques and devices for controlling or compensating for both the first-order and high-order PMD effects in an optical signal by processing the signal in a fixed DGD stage and a variable DGD stage in sequence.
    Type: Application
    Filed: September 4, 2001
    Publication date: June 20, 2002
    Inventors: Qian Yu, Lianshan Yan, Saggeon Lee, Alane E. Willner