Patents by Inventor Shifu Yuan

Shifu Yuan 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: 6904195
    Abstract: An apparatus and method of controlling optical loss in an optical switch to equalize optical power or loss in a group of optical signals in an optical transmission system relatively insensitive to mechanical vibration. In one embodiment a group of optical signals is input into an optical switch and selected optical signals are variably attenuated using synchronized control to two mirrors in order to provide more uniform power distribution among the group of optical signals without enhancing vibration sensitivity of the optical switch.
    Type: Grant
    Filed: July 8, 2003
    Date of Patent: June 7, 2005
    Assignee: Calient Networks, Inc.
    Inventors: John Edward Bowers, Shifu Yuan, Roger Helkey, Xuezhe Zheng, James R. Sechrist
  • Patent number: 6819815
    Abstract: An optical switch embodiment includes a switching array of arranged to accomplish switching of input light beams to any of a plurality of output channels and an array of beam monitoring elements for indirectly measuring and providing information used for adjusting output beams. The beam monitoring element further includes means for measuring the angular misalignment and the positional misalignment of a monitor beam and adjusting the reflectors based on monitor beam information such that optical beams are output from the switch having the desired optical characteristics, such as optimized power. Another optical switch embodiment includes an array of rhomboid prism assemblies positioned to receive the output beams from the switching array and such that the beams are split into substantially parallel working and monitor beams.
    Type: Grant
    Filed: December 12, 2001
    Date of Patent: November 16, 2004
    Assignee: Calient Networks
    Inventors: Charles Corbalis, John E. Bowers, Shifu Yuan, David Welsh, Roger J. Helkey
  • Publication number: 20040081390
    Abstract: An apparatus and method of controlling optical loss in an optical switch to equalize optical power or loss in a group of optical signals in an optical transmission system relatively insensitive to mechanical vibration. In one embodiment a group of optical signals is input into an optical switch and selected optical signals are variably attenuated using synchronized control to two mirrors in order to provide more uniform power distribution among the group of optical signals without enhancing vibration sensitivity of the optical switch.
    Type: Application
    Filed: July 8, 2003
    Publication date: April 29, 2004
    Applicant: Calient Networks, Inc.
    Inventors: John Edward Bowers, Shifu Yuan, Roger Helkey, Xuezhe Zheng, James R. Sechrist
  • Patent number: 6597825
    Abstract: An all-optical switch includes an array of input optical fibers and an array of output optical fibers. A rhomboidal prism beam splitter is positioned in operative relationship with the array of input fibers such that when an array of optical beams is propagated from the array of input optical fibers, the beam splitter splits the array of optical beams into a signal path and a tap path. The rhomboidal prism beam splitter includes a partial internal reflection (PIR) surface and a total internal reflection (TIR) surface. The PIR surface and the TIR surface cooperate to split the array of optical beams into the signal path and the tap path such that the signal path is substantially parallel to the tap path upon exiting the beam splitter.
    Type: Grant
    Filed: October 30, 2001
    Date of Patent: July 22, 2003
    Assignee: Calient Networks, Inc.
    Inventors: Shifu Yuan, Xuezhe Zheng
  • Patent number: 6160665
    Abstract: A system, method and apparatus for performing optical beamsplitting are disclosed. In a preferred embodiment, a high extinction ratio polarization beamsplitter comprises at least two polarized beamsplitting surfaces that are aligned parallel to each other. The beamsplitter receives a first input light beam that is incident on a first polarized beamsplitting surface. The beamsplitter receives a second input light beam that is also incident on the first polarized beamsplitting surface. In a preferred embodiment, the first and second input light beams have a cross point that is not incident on such first polarized beamsplitting surface. Further, in a preferred embodiment, each of the first and second input light beams are incident on such first polarized beamsplitting surface at a point that is not its center point. Cross talk noise is reduced in a preferred embodiment by directing resulting noise to a point that is not co-linear with an output signal.
    Type: Grant
    Filed: June 4, 1999
    Date of Patent: December 12, 2000
    Assignee: Chorum Technologies Inc.
    Inventor: Shifu Yuan