Patents by Inventor David F. Welch

David F. Welch 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: 8660020
    Abstract: Embodiments of the present invention compensate for skew across a wavelength division multiplexed network. The network is a wavelength division multiplexed optical transport network. The skew compensation can be performed electrically or optically. It can be performed on the transmission side of the network, the receiver side of the network or at any intermediary node on the network.
    Type: Grant
    Filed: October 12, 2007
    Date of Patent: February 25, 2014
    Assignee: Infinera Corporation
    Inventors: Drew D. Perkins, David F. Welch, Ting-Kuang Chiang, Edward E. Sprague, Parthiban Kandappan, Stephen G. Grubb, Prasad Paranjape
  • Patent number: 8655190
    Abstract: Consistent with the present disclosure, data, in digital form, is received by a transmit nodes of an optical communication, and converted to analog signal by a digital-to-analog converter (DAC) to drive a modulator. The modulator, in turn, modulates light at one of a plurality of wavelengths in accordance with the received data. The modulated light is then transmitted over an optical communication path to a receive node. At the receive node, the modulated optical signal, as well as other modulated optical signals are supplied to a photodetector circuit, which receives additional light at one of the optical signal wavelengths from a local oscillator laser. An analog-to-digital converter (ADC) is provided in the receive node to convert the electrical signals output from the photodetector into digital form. The output from the ADC is then filtered in the electrical domain, such that optical demultiplexing of individual channels is unnecessary.
    Type: Grant
    Filed: October 5, 2010
    Date of Patent: February 18, 2014
    Assignee: Infinera Corporation
    Inventors: Kuang-Tsan Wu, John D. McNicol, David F. Welch, Stephen G. Grubb, Pierre Mertz
  • Patent number: 8655169
    Abstract: Consistent with the present disclosure, based on system requirements or in response to an increase in optical signal-to-noise level of an optical channel, such as a WDM channel, additional FEC bits are inserted into and replace selected data payload bits in each frame carried by the channel. The replaced data payload bits may then be transmitted in subsequent frames on the same channel. As a result, the transmitted frames have a reduced data payload rate, but a higher coding gain. Alternatively, the replaced data payload bits may be included in frames transmitted on another optical channel. In that case, the frames carried by the two channels typically have the same bit length or number of bits and may thus be compliant with the frame length requirements of G.709, for example. Preferably, the number of coding bits may be changed dynamically to obtain different coding gains.
    Type: Grant
    Filed: September 29, 2008
    Date of Patent: February 18, 2014
    Assignee: Infinera Corporation
    Inventors: Drew D. Perkins, David F. Welch
  • Patent number: 8639118
    Abstract: Consistent with the present disclosure, data, in digital form, is received by a transmit nodes of an optical communication, and converted to analog signal by a digital-to-analog converter (DAC) to drive a modulator. The modulator, in turn, modulates light at one of a plurality of wavelengths in accordance with the received data. The modulated light is then transmitted over an optical communication path to a receive node. At the receive node, the modulated optical signal, as well as other modulated optical signals are supplied to a photodetector circuit, which receives additional light at one of the optical signal wavelengths from a local oscillator laser. An analog-to-digital converter (ADC) is provided in the receive node to convert the electrical signals output from the photodetector into digital form. The output from the ADC is then filtered in the electrical domain, such that optical demultiplexing of individual channels is unnecessary.
    Type: Grant
    Filed: October 5, 2010
    Date of Patent: January 28, 2014
    Assignee: Infinera Corporation
    Inventors: Kuang-Tsan Wu, John D. McNicol, David F. Welch, Stephen G. Grubb, Pierre Mertz
  • Patent number: 8548333
    Abstract: The present invention provides for a transceiver comprising a transmitter portion and a receiver portion. The transmitter portion includes a laser, the laser providing an optical signal having one of a plurality of wavelengths. The optical signal from the laser is modulated to create a first wavelength-division multiplexed signal at an output of the transceiver. The optical signal from the laser is also used by a demultiplexer to demultiplexer a second wavelength-division multiplexed signal at an input of the transceiver. The use of the optical signal from the laser in both modulation and demodulation of wavelength-division multiplexed signals results in a transceiver having fewer discrete components resulting in a compact design and reduced costs.
    Type: Grant
    Filed: April 2, 2010
    Date of Patent: October 1, 2013
    Assignee: Infinera Corporation
    Inventors: Radhakrishnan L. Nagarajan, Masaki Kato, Fred A. Kish, Jr., David F. Welch, Charles H. Joyner
  • Patent number: 8521020
    Abstract: A forward error correction (FEC) communication device that includes a transmitter photonic integrated circuit (TxPIC) or a receiver photonic integrated circuit (RxPIC) and a FEC device for FEC coding at least one channel with a first error rate and at least one additional channel with a second error rate, wherein the first error rate is greater than the second error rate. The TxPIC chip is a monolithic multi-channel chip having an array of modulated sources integrated on the chip, each operating at a different wavelength, wherein at least one of the modulated sources is modulated with a respective FEC encoded signal. The TxPIC also includes an integrated wavelength selective combiner for combining the channels for transport over an optical link.
    Type: Grant
    Filed: June 7, 2010
    Date of Patent: August 27, 2013
    Assignee: Infinera Corporation
    Inventors: David F. Welch, Drew D. Perkins, Fred A. Kish, Jr., Ting-Kuang Chiang
  • Publication number: 20130066679
    Abstract: A computer device receives a list of events, and generates possible outcomes of the events. Each one of the possible outcomes indicates which ones of the events occur and which ones of the events do not occur. The computer device receives a request for forecast information for an item associated with two or more of the events. The computer device further retrieves data, from the possible outcomes, for the item. The computer device generates the forecast, for the item, based on the data. The computer device also uses the forecast to generate a plan to provide or to provide the item or a product associated with the item.
    Type: Application
    Filed: September 14, 2011
    Publication date: March 14, 2013
    Applicant: INFINERA CORPORATION
    Inventors: David F. WELCH, Josue I. KURI, Daniel REIF
  • Patent number: 8300994
    Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.
    Type: Grant
    Filed: February 7, 2011
    Date of Patent: October 30, 2012
    Assignee: Infinera Corporation
    Inventors: David F. Welch, Vincent G. Dominic, Fred A. Kish, Jr., Mark J. Missey, Radhakrishnan L. Nagarajan, Atul Mathur, Frank H. Peters, Robert B. Taylor, Matthew L. Mitchell, Alan C. Nilsson, Stephen G. Grubb, Richard P. Schneider, Charles H. Joyner, Ting-Kuang Chiang, Marco E. Sosa
  • Publication number: 20120251119
    Abstract: Consistent with the present disclosure, data, in digital form, is received by a transmit node of an optical communication, and converted to analog signal by a digital-to-analog converter (DAC) to drive a modulator. The modulator, in turn, modulates light at one of a plurality of wavelengths in accordance with the received data forming a plurality of corresponding carriers. The plurality of carriers are then optically combined with a fixed spacing combiner to form a superchannel of a fixed capacity. Accordingly, the number of carriers are selected according to a modulation format and symbol rate to realize the fixed capacity, for example. The superchannel is then transmitted over an optical communication path to a receive node. At the receive node, the superchannel is optically demultiplexed from a plurality of other superchannels.
    Type: Application
    Filed: April 1, 2011
    Publication date: October 4, 2012
    Inventors: John D. McNicol, Matthew L. Mitchell, David F. Welch
  • Patent number: 8259703
    Abstract: Embodiments of the present invention determine skew relative to a plurality of communication paths on a network system. The network is a wavelength division multiplexed optical transport network. The plurality of communication paths involves different signal and path attributes such as a plurality of carrier wavelengths, optical carrier groups, physical communication paths (different nodes, different fibers along a same path, or any combination of the foregoing), or any other differentiating factors between two paths.
    Type: Grant
    Filed: September 17, 2007
    Date of Patent: September 4, 2012
    Assignee: Infinera Corporation
    Inventors: Drew D. Perkins, David F. Welch, Ting-Kuang Chiang, Edward E. Sprague, Parthiban Kandappan, Steven G. Grubb, Prasad Paranjape, Biao Lu
  • Patent number: 8184929
    Abstract: An optical transmitter comprises a monolithic transmitter photonic integrated circuit (TxPIC) chip that includes an array of modulated sources formed on the PIC chip and having different operating wavelengths approximating a standardized wavelength grid and providing signal outputs of different wavelengths. A wavelength selective combiner is formed on the PIC chip having a wavelength grid passband response approximating the wavelength grid of the standardized wavelength grid. The signal outputs of the modulated sources optically coupled to inputs of the wavelength selective combiner to produce a combined signal output from the combiner. A first wavelength tuning element coupled to each of the modulated sources and a second wavelength tuning element coupled to the wavelength selective combiner. A wavelength monitoring unit is coupled to the wavelength selective combiner to sample the combined signal output.
    Type: Grant
    Filed: December 29, 2008
    Date of Patent: May 22, 2012
    Assignee: Infinera Corporation
    Inventors: Fred A. Kish, Jr., Charles H. Joyner, David F. Welch, Robert B. Taylor, Alan C. Nilsson
  • Patent number: 8175113
    Abstract: Embodiments of the present invention route a wavelength division multiplexed signal across multiple communication paths using skew characteristics of at least some of the communication paths. The network is a wavelength division multiplexed optical transport network. The plurality of communication paths involves different signal and path attributes such as a plurality of carrier wavelengths, optical carrier groups, physical communication paths (different nodes, different fibers along a same path, or any combination of the foregoing), or any other differentiating factors between two paths.
    Type: Grant
    Filed: June 30, 2008
    Date of Patent: May 8, 2012
    Assignee: Infinera Corporation
    Inventors: Drew D. Perkins, David F. Welch, Ting-Kuang Chiang, Charles H. Joyner, Edward E. Sprague, Parthiban Kandappan, Stephen Grubb, Prasad Paranjape
  • Publication number: 20120082460
    Abstract: Consistent with the present disclosure, data, in digital form, is received by a transmit nodes of an optical communication, and converted to analog signal by a digital-to-analog converter (DAC) to drive a modulator. The modulator, in turn, modulates light at one of a plurality of wavelengths in accordance with the received data. The modulated light is then transmitted over an optical communication path to a receive node. At the receive node, the modulated optical signal, as well as other modulated optical signals are supplied to a photodetector circuit, which receives additional light at one of the optical signal wavelengths from a local oscillator laser. An analog-to-digital converter (ADC) is provided in the receive node to convert the electrical signals output from the photodetector into digital form. The output from the ADC is then filtered in the electrical domain, such that optical demultiplexing of individual channels is unnecessary.
    Type: Application
    Filed: October 5, 2010
    Publication date: April 5, 2012
    Inventors: Kuang-Tsan Wu, John D. McNicol, David F. Welch, Stephen G. Grubb, Pierre Mertz
  • Publication number: 20120082466
    Abstract: Consistent with the present disclosure, data, in digital form, is received by a transmit nodes of an optical communication, and converted to analog signal by a digital-to-analog converter (DAC) to drive a modulator. The modulator, in turn, modulates light at one of a plurality of wavelengths in accordance with the received data. The modulated light is then transmitted over an optical communication path to a receive node. At the receive node, the modulated optical signal, as well as other modulated optical signals are supplied to a photodetector circuit, which receives additional light at one of the optical signal wavelengths from a local oscillator laser. An analog-to-digital converter (ADC) is provided in the receive node to convert the electrical signals output from the photodetector into digital form. The output from the ADC is then filtered in the electrical domain, such that optical demultiplexing of individual channels is unnecessary.
    Type: Application
    Filed: October 5, 2010
    Publication date: April 5, 2012
    Inventors: Kuang-Tsan Wu, John D. McNicol, David F. Welch, Stephen G. Grubb, Pierre Mertz
  • Publication number: 20120082453
    Abstract: Consistent with the present disclosure, data, in digital form, is received by a transmit nodes of an optical communication, and converted to analog signal by a digital-to-analog converter (DAC) to drive a modulator. The modulator, in turn, modulates light at one of a plurality of wavelengths in accordance with the received data. The modulated light is then transmitted over an optical communication path to a receive node. At the receive node, the modulated optical signal, as well as other modulated optical signals are supplied to a photodetector circuit, which receives additional light at one of the optical signal wavelengths from a local oscillator laser. An analog-to-digital converter (ADC) is provided in the receive node to convert the electrical signals output from the photodetector into digital form. The output from the ADC is then filtered in the electrical domain, such that optical demultiplexing of individual channels is unnecessary.
    Type: Application
    Filed: October 5, 2010
    Publication date: April 5, 2012
    Inventors: Kuang-Tsan Wu, John D. McNicol, David F. Welch, Stephen G. Grubb, Pierre Mertz
  • Publication number: 20120082459
    Abstract: Consistent with the present disclosure, data, in digital form, is received by a transmit nodes of an optical communication, and converted to analog signal by a digital-to-analog converter (DAC) to drive a modulator. The modulator, in turn, modulates light at one of a plurality of wavelengths in accordance with the received data. The modulated light is then transmitted over an optical communication path to a receive node. At the receive node, the modulated optical signal, as well as other modulated optical signals are supplied to a photodetector circuit, which receives additional light at one of the optical signal wavelengths from a local oscillator laser. An analog-to-digital converter (ADC) is provided in the receive node to convert the electrical signals output from the photodetector into digital form. The output from the ADC is then filtered in the electrical domain, such that optical demultiplexing of individual channels is unnecessary.
    Type: Application
    Filed: October 5, 2010
    Publication date: April 5, 2012
    Inventors: Kuang-Tsan Wu, John D. McNicol, David F. Welch, Stephen G. Grubb, Pierre Mertz
  • Publication number: 20120057873
    Abstract: Consistent with the present disclosure, an optical communication system is provided in which client data is input to a first node and output from a second node, spaced from the first node, with little delay. In one example, the delay is reduced by including higher order Raman amplifiers that provide a substantially uniform gain along the length of a fiber optic link, thereby reducing the number of EDFAs that may otherwise be installed along the optical fiber link or eliminating such EDFAs entirely. In another example, FEC encoding and decoding are not employed, thereby reducing the delay even further.
    Type: Application
    Filed: September 3, 2010
    Publication date: March 8, 2012
    Inventors: PAUL R. MORKEL, David F. Welch
  • Patent number: 8111685
    Abstract: Embodiments of the present invention route a wavelength division multiplexed signal across multiple communication paths using skew characteristics of at least some of the communication paths. The network is a wavelength division multiplexed optical transport network. The plurality of communication paths involves different signal and path attributes such as a plurality of carrier wavelengths, optical carrier groups, physical communication paths (different nodes, different fibers along a same path, or any combination of the foregoing), or any other differentiating factors between two paths.
    Type: Grant
    Filed: September 6, 2007
    Date of Patent: February 7, 2012
    Assignee: Infinera Corporation
    Inventors: Drew D. Perkins, David F. Welch, Ting-Kuang Chiang, Edward E. Sprague, Parthiban Kandappan, Stephen G. Grubb, Prasad Paranjape
  • Publication number: 20110249936
    Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.
    Type: Application
    Filed: February 7, 2011
    Publication date: October 13, 2011
    Inventors: David F. Welch, Vincent G. Dominic, Fred A. Kish, JR., Mark J. Missey, Radhakrishnan L. Nagarajan, Atul Mathur, Frank H. Peters, Robert B. Taylor, Matthew L. Mitchell, Alan C. Nilsson, Stephen G. Grubb, Richard P. Schneider, Charles H. Joyner, Ting-Kuang Chiang, Marco E. Sosa
  • Publication number: 20110243556
    Abstract: The present invention provides for a transceiver comprising a transmitter portion and a receiver portion. The transmitter portion includes a laser, the laser providing an optical signal having one of a plurality of wavelengths. The optical signal from the laser is modulated to create a first wavelength-division multiplexed signal at an output of the transceiver. The optical signal from the laser is also used by a demultiplexer to demultiplexer a second wavelength-division multiplexed signal at an input of the transceiver. The use of the optical signal from the laser in both modulation and demodulation of wavelength-division multiplexed signals results in a transceiver having fewer discrete components resulting in a compact design and reduced costs.
    Type: Application
    Filed: April 2, 2010
    Publication date: October 6, 2011
    Inventors: Radhakrishnan L. Nagarajan, Masaki Kato, Fred A. Kish, JR., David F. Welch, Charles H. Joyner