Patents Represented by Attorney, Agent or Law Firm David A. Fox
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Patent number: 6804273Abstract: A controller for use with an optical device having an optical source and a frequency reference element. The controller includes a frequency processing module coupled to the optical device. The frequency processing module generates an error signal indicative of a deviation between the output frequency of the optical source and a reference frequency corresponding to a reference point. A driver module communicates with the optical device and the frequency processing module. The driver module adjusts a parameter of the optical source in response to the error signal. An offset processing module is coupled to the frequency processing module. The offset processing module derives an offset signal based on an estimate of a temperature of the frequency reference element. The offset processing module provides the offset signal to the frequency processing module which updates the reference point in response to the offset.Type: GrantFiled: March 19, 2002Date of Patent: October 12, 2004Assignee: Ciena CorporationInventor: Paolo Sacchetto
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Patent number: 6802652Abstract: A recessed cable management assembly for use in an interconnect assembly. The cable management assembly includes a cassette having a spool for receiving and retaining a length of a cable. A substrate includes an interconnect connector which is coupled to the cable. The substrate includes a cut-out sized to receive the cable management assembly such that the cable management assembly is recessed within the substrate.Type: GrantFiled: October 4, 2002Date of Patent: October 12, 2004Assignee: Ciena CorporationInventors: Paolo Sacchetto, Ralph T. Hofmeister, Narasinha Parasnis
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Patent number: 6782000Abstract: A user interface for managing connections in a communication network cross connect. The user interface provides for creation, viewing and removing connections in the cross connect. When displaying connections, a slice value and granularity may be adjusted to allow for effective viewing of connections having high data rates. The user interface may include a search tool for locating connections and/or a protection setup routine to facilitate establish protection connections.Type: GrantFiled: October 31, 2002Date of Patent: August 24, 2004Assignee: CIENA CorporationInventors: Mahesh Subramanian, Suresh Muthu, Kuga P. Visagamani
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Patent number: 6757114Abstract: An optical filter aligner/separator device for retaining optical filters in a desired position, the optical filters having an optical filter height, the device includes: a top frame having a top frame cut out section; a bottom frame having a bottom side and a bottom frame cut out section, the bottom frame coupled to the top frame, the bottom frame cut out section aligning with the top frame cut out section; and a wire mesh disposed between the top frame and the bottom frame, the wire mesh disposed at the cut out section, the wire mesh having a height from the bottom side of the bottom frame that is less than the optical filter height.Type: GrantFiled: October 31, 2001Date of Patent: June 29, 2004Assignee: Ciena CorporationInventors: Lou Rodriguez, Gary Kles
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Patent number: 6742154Abstract: A network optimization method measures the line bit error rate (BER) at a receiver by counting forward error correction corrected errors, and adjusts network parameters to minimize the corrected error rate. Adjustable parameters include, among other things, transmitter extinction ratio, transmitter polarization, and dispersion. The method includes sweeping an adjustable parameter while monitoring the FEC corrected bit error rates at the receiver, and then extrapolating an optimum value of the parameter. In this way, the corrected BER can be maintained below the predetermined BER limit while the digital communication network is in-service.Type: GrantFiled: May 25, 2000Date of Patent: May 25, 2004Assignee: Ciena CorporationInventor: Chris Barnard
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Patent number: 6677591Abstract: A method for detecting defects in an optical device. The method includes obtaining an optical device that is a component of an optical communications system carrying information signals at a communications wavelength. Infrared light is applied to the optical device. The infrared light has a wavelength corresponding to the communications wavelength. An image of the optical device is obtained while the optical device is transmitting the infrared light. The image provides multidimensional data including positional values and intensity values. The image is then analyzed to detect defects in the optical device.Type: GrantFiled: January 30, 2002Date of Patent: January 13, 2004Assignee: Ciena CorporationInventor: Wonoh Kim
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Patent number: 6616348Abstract: A method for operating a redundant optical communication network has at least two network transmission paths, assigns first and second protection protocols to switched signals and secondary signals respectively, adds and drops the switched signals and secondary signals on the at least two network transmission paths, makes the switched signals and the secondary signals to counter-propagate along the at least two network transmission paths, therefore, the redundant optical communication network can support different data types and different protection mechanisms.Type: GrantFiled: January 28, 2000Date of Patent: September 9, 2003Assignee: Ciena CorporationInventor: Chris Barnard
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Patent number: 6614589Abstract: The invention includes a method for controlling amplifier output power in an optical communications network. A first transmission parameter is determined at a first amplifier. In an exemplary embodiment, the first transmission parameter is a composite express signal to noise ratio. The total output power of a downstream amplifier is adjusted in response to the first transmission parameter. A system for implementing the method is also disclosed.Type: GrantFiled: July 27, 2001Date of Patent: September 2, 2003Assignee: Ciena CorporationInventors: James E. DeGrange, Jr., Sridhar Balakrishnan
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Method and system for controlling Raman gain flatness sensitivity to pump laser wavelength variation
Patent number: 6525870Abstract: An exemplary embodiment of the invention is a Raman amplifier for use in an optical communications network. The Raman amplifier includes a plurality of pump lasers and a plurality of wavelength control modules, each associated with one of the pump lasers. Each wavelength control module includes a fiber Bragg grating optically coupled to a respective one of the plurality of pump lasers. The fiber Bragg grating receives a pump laser output from one of the pump lasers and generates a wavelength control module output. A temperature sensor is in thermal contact with the fiber Bragg grating and generates a temperature signal indicative of a temperature of the fiber Bragg grating. A controller is operatively connected to the temperature sensor and generates a control signal in response to the temperature signal. A thermal regulator is in thermal contact with the fiber Bragg grating and adjusts the temperature of the fiber Bragg grating in response to the control signal.Type: GrantFiled: July 26, 2001Date of Patent: February 25, 2003Assignee: Ciena CorporationInventors: Si Hyung Cho, Jon Tsou, Jun Bao, Balakrishnan Sridhar -
Patent number: 6325044Abstract: An exemplary embodiment of the invention is a method of controlling fuel injection timing in a compression ignition engine including at least one cylinder. The method includes monitoring engine throttle position and change. One of an acceleration and a load ascending transient operating mode is detected in response to the monitoring of throttle position and change. Fuel injection timing for the at least one cylinder is controlled in accordance with a predetermined timing schedule in response to the detection of one of an acceleration and a load ascending transient operating mode. A system for implementing the method is also disclosed.Type: GrantFiled: March 20, 2000Date of Patent: December 4, 2001Assignee: General Electric CompanyInventors: Gong Chen, Bertrand Dahung Hsu, Robert Douglas Cryer