Patents by Inventor Charles John Donaldson

Charles John Donaldson 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: 6885500
    Abstract: A method and apparatus is provided for controlling the optical output power from an optical amplifier arrangement. The arrangement includes a rare-earth doped fiber for imparting gain to an optical input signal propagating therethrough, a pump source for supplying pump power to the rare-earth doped fiber, and a tap for receiving a portion of the output power generated by the rare-earth doped fiber and converting it to a control signal. A controller is also provided for receiving the control signal and generating a bias current in response thereto for driving the pump source. The method begins by receiving an optical input signal that is being amplitude modulated at a prescribed frequency. The slew rate of the controller is adjusted so that the bias current drives the pump source to generate pump power that cannot vary at a rate greater than a slew-rate limit established by the controller. In this way resonance between the input signal and the frequency of the feedback control loop can be avoided.
    Type: Grant
    Filed: August 4, 2003
    Date of Patent: April 26, 2005
    Assignee: General Instrument Corporatin
    Inventors: Eric James Converse, David Ciaffa, Charles John Donaldson
  • Publication number: 20040027650
    Abstract: A method and apparatus is provided for controlling the optical output power from an optical amplifier arrangement. The arrangement includes a rare-earth doped fiber for imparting gain to an optical input signal propagating therethrough, a pump source for supplying pump power to the rare-earth doped fiber, and a tap for receiving a portion of the output power generated by the rare-earth doped fiber and converting it to a control signal. A controller is also provided for receiving the control signal and generating a bias current in response thereto for driving the pump source. The method begins by receiving an optical input signal that is being amplitude modulated at a prescribed frequency. The slew rate of the controller is adjusted so that the bias current drives the pump source to generate pump power that cannot vary at a rate greater than a slew-rate limit established by the controller. In this way resonance between the input signal and the frequency of the feedback control loop can be avoided.
    Type: Application
    Filed: August 4, 2003
    Publication date: February 12, 2004
    Inventors: Eric James Converse, David Ciaffa, Charles John Donaldson
  • Patent number: 6611374
    Abstract: A method and apparatus is provided for controlling the optical output power from an optical amplifier arrangement. The arrangement includes a rare-earth doped fiber for imparting gain to an optical input signal propagating therethrough, a pump source for supplying pump power to the rare-earth doped fiber, and a tap for receiving a portion of the output power generated by the rare-earth doped fiber and converting it to a control signal. A controller is also provided for receiving the control signal and generating a bias current in response thereto for driving the pump source. The method begins by receiving an optical input signal that is being amplitude modulated at a prescribed frequency. The slew rate of the controller is adjusted so that the bias current drives the pump source to generate pump power that cannot vary at a rate greater than a slew-rate limit established by the controller. In this way resonance between the input signal and the frequency of the feedback control loop can be avoided.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: August 26, 2003
    Assignee: General Instrument Corporation
    Inventors: Eric James Converse, David Ciaffa, Charles John Donaldson
  • Publication number: 20030142396
    Abstract: A method and apparatus is provided for controlling the optical output power from an optical amplifier arrangement. The arrangement includes a rare-earth doped fiber for imparting gain to an optical input signal propagating therethrough, a pump source for supplying pump power to the rare-earth doped fiber, and a tap for receiving a portion of the output power generated by the rare-earth doped fiber and converting it to a control signal. A controller is also provided for receiving the control signal and generating a bias current in response thereto for driving the pump source. The method begins by receiving an optical input signal that is being amplitude modulated at a prescribed frequency. The slew rate of the controller is adjusted so that the bias current drives the pump source to generate pump power that cannot vary at a rate greater than a slew-rate limit established by the controller. In this way resonance between the input signal and the frequency of the feedback control loop can be avoided.
    Type: Application
    Filed: January 31, 2002
    Publication date: July 31, 2003
    Inventors: Eric James Converse, David Ciaffa, Charles John Donaldson