Patents by Inventor Ruo Ding Li

Ruo Ding Li 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: 6580531
    Abstract: A method and apparatus for in-circuit biasing of a modulated laser and bit error rate testing of an optical transmitter and/or optical receiver under the control of a test controller. The test controller is communicably coupled to an interface of a module under test, as well as to external test equipment. The test controller modifies operational parameters of the modulated laser, in order to obtain a desired output power and to obtain a predetermined extinction ratio. The operational parameters of the laser include a laser bias current, an electro-absorption modulator offset bias current and a modulation depth. The disclosed test controller also determines whether the optical transmitter and/or receiver exhibit acceptable bit error rates. The disclosed test controller uses a variable optical attenuator, in combination with an erbium-doped fiber amplifier (EDFA) to control an optical signal to noise ratio for a signal terminating at either the transmitter or the receiver of the optical transceiver under test.
    Type: Grant
    Filed: December 30, 1999
    Date of Patent: June 17, 2003
    Assignee: Sycamore Networks, Inc.
    Inventors: Eric A. Swanson, Ruo Ding Li
  • Patent number: 6490071
    Abstract: A method of optimizing SBS suppression is disclosed for use in an optical communication system including a light guide for transmitting light and means for producing phase modulation of the light using at least first and second tones. In the method, an operational region of SBS suppression is established as a function of the phase modulation of the light such that the operational region identifies combinations of first and second phase modulation levels at which optimum SBS suppression is achieved for the first and second tones. Thereafter, based on the operational region, the first and second phase modulation levels are adjusted such that the system operates with optimum SBS suppression. In one aspect, a contour map and associated method are introduced.
    Type: Grant
    Filed: August 6, 2001
    Date of Patent: December 3, 2002
    Assignee: JDS Uniphase Corporation
    Inventors: Ronald T. Logan, Jr., Ruo Ding Li
  • Publication number: 20020015208
    Abstract: A method of optimizing SBS suppression is disclosed for use in an optical communication system including a light guide for transmitting light and means for producing phase modulation of the light using at least first and second tones. In the method, an operational region of SBS suppression is established as a function of the phase modulation of the light such that the operational region identifies combinations of first and second phase modulation levels at which optimum SBS suppression is achieved for the first and second tones. Thereafter, based on the operational region, the first and second phase modulation levels are adjusted such that the system operates with optimum SBS suppression. In one aspect, a contour map and associated method are introduced.
    Type: Application
    Filed: August 6, 2001
    Publication date: February 7, 2002
    Inventors: Ronald T. Logan, Ruo Ding Li
  • Patent number: 6282003
    Abstract: A method of optimizing SBS suppression is disclosed for use in an optical communication system including a light guide for transmitting light and means for producing phase modulation of the light using at least first and second tones. In the method, an operational region of SBS suppression is established as a function of the phase modulation of the light such that the operational region identifies combinations of first and second phase modulation levels at which optimum SBS suppression is achieved for the first and second tones. Thereafter, based on the operational region, the first and second phase modulation levels are adjusted such that the system operates with optimum SBS suppression. In one aspect, a contour map and associated method are introduced.
    Type: Grant
    Filed: February 2, 1998
    Date of Patent: August 28, 2001
    Assignee: Uniphase Corporation
    Inventors: Ronald T. Logan, Jr., Ruo Ding Li