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: 7079715
    Abstract: A monolithic transmitter photonic integrated circuit (TxPIC) chip comprises an array of modulated sources formed on the PIC chip and having different operating wavelengths according to a standardized wavelength grid and providing signal outputs of different wavelengths. Pluralities of wavelength tuning elements are integrated on the chip, one associated with each of the modulated sources. An optical combiner is formed on the PIC chip and the signal outputs of the modulated sources are optically coupled to one or more inputs of the optical combiner and provided as a combined channel signal output from the combiner. The wavelength tuning elements provide for tuning the operating wavelength of the respective modulated sources to be approximate or to be chirped to the standardized wavelength grid. The wavelength tuning elements are temperature changing elements, current and voltage changing elements or bandgap changing elements.
    Type: Grant
    Filed: October 8, 2002
    Date of Patent: July 18, 2006
    Assignee: Infinera Corporation
    Inventors: Fred A. Kish, Jr., Charles H. Joyner, David F. Welch, Jonas Webjorn, Robert B. Taylor, Alan C. Nilsson
  • Patent number: 7079720
    Abstract: A method of operating an array of laser sources integrated as an array in a single monolithic chip where the steps include designing the laser sources to have different target emission wavelengths so that together they form a spectral emission wavelength grid, coupling outputs from the laser sources to an array of gain/loss elements also integrated on the single monolithic chip, one each receiving the output from a respective laser source; and adjusting the outputs with the gain/loss elements so that the power levels across the laser source array are substantially uniform.
    Type: Grant
    Filed: August 13, 2004
    Date of Patent: July 18, 2006
    Assignee: Infinera Corporation
    Inventors: Fred A. Kish, Jr., Charles H. Joyner, David F. Welch, Robert B. Taylor, Alan C. Nilsson
  • Patent number: 7058246
    Abstract: A monolithic photonic integrated circuit (PIC) chip comprises an array of modulated sources providing a plurality of channel signals of different wavelengths and an optical combiner coupled to receive the channel signals and produce a combined output of the channel signals. The arrays of modulated sources are formed as ridge waveguides to enhance the output power from the respective modulated sources so that the average output power from the sources is approximately 2 to 4 times higher than in the case of comparable arrays of modulated sources formed as buried waveguides.
    Type: Grant
    Filed: October 8, 2002
    Date of Patent: June 6, 2006
    Assignee: Infinera Corporation
    Inventors: Charles H. Joyner, Fred A. Kish, Jr., Frank H. Peters, Atul Mathur, David F. Welch, Andrew G. Dentai, Damien Lambert, Richard P. Schneider, Mark J. Missey
  • Patent number: 7058263
    Abstract: An optical transport network comprises a monolithic transmitter photonic integrated circuit (TxPIC) InP-based chip and a monolithic receiver photonic integrated circuit (RxPIC) InP-based chip.
    Type: Grant
    Filed: May 5, 2005
    Date of Patent: June 6, 2006
    Assignee: Infinera Corporation
    Inventors: David F. Welch, Radhakrishnan L. Nagarajan, Fred A. Kish, Jr., Mark J. Missey, Vincent G. Dominic, Atul Mathur, Frank H. Peters, Charles H. Joyner, Richard P. Schneider, Ting-Kuang Chiang
  • Patent number: 7050666
    Abstract: An optical receiver photonic integrated circuit (RxPIC) system includes a monolithic semiconductor chip having an input to receive a WDM combined channel signal comprising a plurality of optical channel signals of different wavelengths. A chip-integrated decombiner is coupled to the chip input to receive the WDM combined channel signal and separate the same into a plurality of different channel signals having different wavelengths. An array of integrated photodetectors, also integrated on the chip, each receive a separated channel signal and together provide a plurality of electrical signals representative of the optical channel signals. An electronic amplifier receives and amplifies the electrical signals. An electronic dispersion equalization (EDE) circuit is coupled to receive and adjust the amplified electrical signals for timing errors due to imperfect clock recovery of said electrical signals. An clock and data recover (CDR) circuit recovers a signal clock and data signals from the electrical signals.
    Type: Grant
    Filed: January 10, 2005
    Date of Patent: May 23, 2006
    Assignee: Infinera Corporation
    Inventors: David F. Welch, Vincent G. Dominic, Ting-Kuang Chiang
  • Publication number: 20040067006
    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: December 11, 2002
    Publication date: April 8, 2004
    Inventors: David F. Welch, Vincent G. Dominic, Fred A. Kish, 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, Jonas Webjorn, Ting-Kuang Chiang, Robert Grencavich, Vinh D. Nguyen, Donald J. Pavinski, Marco E. Sosa
  • Publication number: 20040033004
    Abstract: A photonic integrated circuits (PICs), also referred to as opto-electronic integrated circuits (OEICs), and more particularly to a PIC in the form of an optical receiver PIC or RxPIC for use in an optical transport networks. Also, an optical transmitter PIC (TxPIC) is also disclosed in conjunction with an RxPIC in an optical transport network. The chip is cast from an InP wafer and is made from Group III-V elemental materials in the InGaAsP/InP regime with fabrication accomplished through selective metalorganic vapor phase epitaxy (MOVPE) or also known as metalorganic chemical vapor deposition (MOCVD). Integrated on the chip, starting at the input end which is coupled to receive multiplexed optical data signals from an optical transport network is an optical amplifier, an optical demultiplexer, and a plurality of on-chip photodiodes (PDs) each to receive a demultiplexed data signal from the AWG DEMUX for optical-to-electrical signal conversion.
    Type: Application
    Filed: October 8, 2002
    Publication date: February 19, 2004
    Inventors: David F. Welch, Radhakrishnan L. Nagarajan, Fred A. Kish, Mark J. Missey, Vincent G. Dominic, Atul Mathur, Frank H. Peters, Charles H. Joyner, Richard P. Schneider, Ting-Kuang Chiang
  • Patent number: 6603595
    Abstract: An optical amplifier with a flattened wideband response is obtained by coupling counter-propagating pumping energy into an optical waveguide to cause Raman amplification in the optical waveguide, and by reflecting an amplified signal received from the optical waveguide into an output waveguide using a reflector having a spectral characteristic that is complementary to the spectral gain characteristic of the Raman amplification.
    Type: Grant
    Filed: June 26, 2002
    Date of Patent: August 5, 2003
    Assignee: JDS Uniphase Corporation
    Inventors: David F. Welch, Robert J. Lang, Edward C. Vail, Mehrdad Ziari
  • Patent number: 6580552
    Abstract: An optical amplifier includes a plurality of optical paths each carrying an optical signal and each including active optical fiber. A shared pump laser is coupled to the plurality of optical paths and provides pump power to the plurality of optical paths to individually amplify the optical signals. The plurality of optical paths includes input and output optical isolators and a coupler for coupling the pump power to the optical path. The active optical fiber is doped with an implant selected from the group of rare earth metals, erbium, ytterbium, and both ytterbium and erbium. A variable attenuator can be connected between the pump laser and the coupler of at least one of the plurality of optical paths or adjacent to the output isolator of one of the optical paths. Another optical amplifier serially couples optical signals to the optical path on a common gain media.
    Type: Grant
    Filed: August 27, 2001
    Date of Patent: June 17, 2003
    Assignee: JDS Uniphase Corporation
    Inventor: David F. Welch
  • Publication number: 20030099018
    Abstract: A digital optical network (DON) is a new approach to low-cost, more compact optical transmitter modules and optical receiver modules for deployment in optical transport networks (OTNs). One important aspect of a digital optical network is the incorporation in these modules of transmitter photonic integrated circuit (TxPIC) chips and receiver photonic integrated circuit (TxPIC) chips in lieu of discrete modulated sources and detector sources with discrete multiplexers or demultiplexers.
    Type: Application
    Filed: October 8, 2002
    Publication date: May 29, 2003
    Inventors: Jagdeep Singh, Drew D. Perkins, David F. Welch, Mark Yin, Fred A. Kish, Stephen G. Grubb, Robert B. Taylor, Vincent G. Dominic, Matthew L. Mitchell
  • Publication number: 20030095737
    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: October 8, 2002
    Publication date: May 22, 2003
    Inventors: David F. Welch, Vincent G. Dominic, Fred A. Kish, 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, Jonas Webjorn, Drew D. Perkins
  • Publication number: 20030095736
    Abstract: A monolithic transmitter photonic integrated circuit (TxPIC) chip comprises an array of modulated sources formed on the PIC chip and having different operating wavelengths according to a standardized wavelength grid and providing signal outputs of different wavelengths. Pluralities of wavelength tuning elements are integrated on the chip, one associated with each of the modulated sources. An optical combiner is formed on the PIC chip and the signal outputs of the modulated sources are optically coupled to one or more inputs of the optical combiner and provided as a combined channel signal output from the combiner. The wavelength tuning elements provide for tuning the operating wavelength of the respective modulated sources to be approximate or to be chirped to the standardized wavelength grid. The wavelength tuning elements are temperature changing elements, current and voltage changing elements or bandgap changing elements.
    Type: Application
    Filed: October 8, 2002
    Publication date: May 22, 2003
    Inventors: Fred A. Kish, Charles H. Joyner, David F. Welch, Jonas Webjorn, Robert B. Taylor, Alan C. Nilsson
  • Publication number: 20030081878
    Abstract: A monolithic photonic integrated circuit (PIC) chip comprises an array of modulated sources providing a plurality of channel signals of different wavelengths and an optical combiner coupled to receive the channel signals and produce a combined output of the channel signals. The arrays of modulated sources are formed as ridge waveguides to enhance the output power from the respective modulated sources so that the average output power from the sources is approximately 2 to 4 times higher than in the case of comparable arrays of modulated sources formed as buried waveguides.
    Type: Application
    Filed: October 8, 2002
    Publication date: May 1, 2003
    Inventors: Charles H. Joyner, Fred A. Kish, Frank H. Peters, Atul Mathur, David F. Welch, Andrew G. Dentai, Damien Lambert, Richard P. Schneider, Mark J. Missey
  • Publication number: 20030076577
    Abstract: A lossless optical link in an optical transmission system comprises an optical fiber that is configured to produce Raman gain and provide for Raman distributed gain, via one or more pump sources, along the fiber so that, as an end result, the gain experienced by one or more propagating signals in the fiber link is made fairly uniform along the link or at least a portion of the optical link, such as not vary, for example, no more than five dB along the length of the optical fiber. The several embodiments disclosed provide for different optical pump/component architectures to achieve this end result.
    Type: Application
    Filed: December 22, 2000
    Publication date: April 24, 2003
    Inventors: Vincent G. Dominic, David F. Welch, Robert G. Waarts, Stuart MacCormack, Mehrdad Ziari, Robert J. Lang, Donald R. Scifres
  • Publication number: 20030039027
    Abstract: An optical amplifier includes a plurality of optical paths each carrying an optical signal and each including active optical fiber. A shared pump laser is coupled to the plurality of optical paths and provides pump power to the plurality of optical paths to individually amplify the optical signals. The plurality of optical paths includes input and output optical isolators and a coupler for coupling the pump power to the optical path. The active optical fiber is doped with an implant selected from the group of rare earth metals, erbium, ytterbium, and both ytterbium and erbium. A variable attenuator can be connected between the pump laser and the coupler of at least one of the plurality of optical paths or adjacent to the output isolator of one of the optical paths. Another optical amplifier serially couples optical signals to the optical path on a common gain media.
    Type: Application
    Filed: August 27, 2001
    Publication date: February 27, 2003
    Inventor: David F. Welch
  • Patent number: 6489985
    Abstract: A laser marking system includes a high power fiber laser with a double clad fiber having a doped core surrounded by an inner pump cladding and providing an optical output for marking; a high power laser diode source for pumping the double clad fiber laser via an input into the inner pump cladding; an optical scanner coupled to receive the marking output from the double clad fiber laser to scan the output over a surface of an article to be marked by sweeping the marking output in one, two or three dimensions to form strokes, the completion of which comprises indicia to be marked on the article surface; and a controller to control the operation of the scanner synchronized with the modulation of the laser diode pump source to initiate the marking output and sweep and modulate the marking optical output in one, two or three dimensions to form strokes comprising the indicia.
    Type: Grant
    Filed: September 21, 2000
    Date of Patent: December 3, 2002
    Assignee: JDS Uniphase Corporation
    Inventors: Mark A. Brodsky, David F. Welch, Yong Yim
  • Publication number: 20020163713
    Abstract: An optical amplifier with a flattened wideband response is obtained by coupling counter-propagating pumping energy into an optical waveguide to cause Raman amplification in the optical waveguide, and by reflecting an amplified signal received from the optical waveguide into an output waveguide using a reflector having a spectral characteristic that is complementary to the spectral gain characteristic of the Raman amplification.
    Type: Application
    Filed: June 26, 2002
    Publication date: November 7, 2002
    Inventors: David F. Welch, Robert J. Lang, Edward C. Vail, Mehrdad Ziari
  • Patent number: 6433920
    Abstract: An optical amplifier with a flattened wideband response is obtained by coupling counter-propagating pumping energy into an optical waveguide to cause Raman amplification in the optical waveguide, and by reflecting an amplified signal received from the optical waveguide into an output waveguide using a reflector having a spectral characteristic that is complementary to the spectral gain characteristic of the Raman amplification.
    Type: Grant
    Filed: September 18, 2000
    Date of Patent: August 13, 2002
    Assignee: JDS Uniphase Corporation
    Inventors: David F. Welch, Robert J. Lang, Edward C. Vail, Mehrdad Ziari
  • Patent number: 6433306
    Abstract: A high power laser optical amplifier system for material processing comprises multiple stage fiber amplifiers with rejection of propagating ASE buildup in and between the amplifier stages as well as elimination of SBS noise providing output powers in the range of about 10 &mgr;J to about 100 &mgr;J or more. The system is driven with a time varying drive signal from a modulated semiconductor laser signal source to produce an optical output allowing modification of the material while controlling its thermal sensitivity by varying pulse shapes or pulse widths supplied at a desire repetition rate via modulation of a semiconductor laser signal source to the system to precisely control the applied power application of the beam relative to the thermal sensitivity of the material to be processed. The high power fiber amplifier system has particular utility in high power applications requiring process treatment of surfaces, such as polymeric, organic, ceramic and metal surfaces, e.g.
    Type: Grant
    Filed: June 2, 2000
    Date of Patent: August 13, 2002
    Assignee: JDS Uniphase Corp.
    Inventors: Stephen G. Grubb, David F. Welch, Raymond Zanoni
  • Patent number: 6411323
    Abstract: Power scaling by multiplexing multiple fiber gain sources with different wave-lengths is useful in printing applications requiring higher optical powers to perform the printing function, such as through thermal inducement in thermal ablation, thermal fusion, thermal diffusion or thermal transfer. A marking system is disclosed using a plurality of laser sources operating at different wavelengths with their respective outputs coupled into a respective single mode fiber. At least one WDM combiner is coupled to receive and combine the laser source outputs into a single output. The combined power single output provides sufficient power intensity to induce thermal marking on a marking medium.
    Type: Grant
    Filed: December 7, 2000
    Date of Patent: June 25, 2002
    Assignee: SDL, Inc.
    Inventors: Robert G. Waarts, David F. Welch