Patents by Inventor David Welch

David 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).

  • Publication number: 20050013332
    Abstract: A method and apparatus operates an array of laser sources as an integrated array on a single substrate or as integrated in an optical transmitter photonic integrated circuit (TxPIC) maintaining the emission wavelengths of such integrated laser sources at their targeted emission wavelengths or at least to more approximate their desired respective emission wavelengths. Wavelength changing elements may accompany the laser sources to bring about the change in their operational or emission wavelength to be corrected to or toward the desired or target emission wavelength. The wavelength changing elements may be comprise of temperature changing elements, current and voltage changing elements or bandgap changing elements.
    Type: Application
    Filed: August 16, 2004
    Publication date: January 20, 2005
    Applicant: Infinera Corporation
    Inventors: Fred Kish, Charles Joyner, David Welch, Robert Taylor, Alan Nilsson
  • Publication number: 20050013331
    Abstract: A method of operating an array of integrated laser sources formed as an integrated array on a single substrate in a photonic integrated circuit (PIC) where the laser sources are designed for operation at different targeted emission wavelengths which, in toto, at least approximate a grid of spatial emission wavelengths. A first wavelength tuning element is associated with each laser source and is adjusted over time so that each laser source maintains its targeted emission wavelength. As an alternative, the drive current to each laser source may be initially set so that each laser source operates at its targeted emission wavelength. Thereafter, adjustments to retune the laser sources to their targeted emission wavelengths are accomplished by the first wavelength tuning elements. The outputs of the laser sources may be combined via an optical combiner to produce a single combined output from the PIC.
    Type: Application
    Filed: August 12, 2004
    Publication date: January 20, 2005
    Applicant: Infinera Corporation
    Inventors: Fred Kish, Charles Joyner, David Welch, Robert Taylor, Alan Nilsson
  • Publication number: 20050013330
    Abstract: A method of tuning optical components integrated on a monolithic chip, such as an optical transmitter photonic integrated circuit (TxPIC), is disclosed where a group of first optical components are each fabricated to have an operating wavelength approximating a wavelength on a standardized or predetermined wavelength grid and are each included with a local wavelength tuning component also integrated in the chip. Each of the first optical components is wavelength tuned through their local wavelength tuning component to achieve a closer wavelength response that approximates their wavelength on the wavelength grid.
    Type: Application
    Filed: August 10, 2004
    Publication date: January 20, 2005
    Applicant: Infinera Corporation
    Inventors: Fred Kish, Charles Joyner, David Welch, Jonas Webjorn, Robert Taylor, Alan Nilsson
  • Publication number: 20050014300
    Abstract: An optical probe and a method for testing an optical chip or device, such as an photonic integrated circuit (PIC), to provide for testing of such devices or circuits while they are still in their in-wafer form and is accomplished by using a an optical probe for interrogation of the circuit where an access is provided in the wafer to one or more of such in-wafer devices or circuits. As one example, the interrogation may be an interrogation beam provided at the access input to the in-wafer device or circuit. As another example, the interrogation may be an optical pickup from the access input to the in-wafer device or circuit.
    Type: Application
    Filed: August 2, 2004
    Publication date: January 20, 2005
    Applicant: Infinera Corporation
    Inventors: David Welch, Fred Kish, Frank Peters, Charles Joyner
  • Patent number: 5980397
    Abstract: A weighted device that attaches to a baseball or softball bat for the purpose of increasing the bat's mass during batting practice thereby increasing a persons strength and improving their bat control, ultimately improving their batting average and batting power. The device can be used during the actual practice of hitting a ball. The device can be attached to the bat at various locations along the tapered portion of the bat.
    Type: Grant
    Filed: April 16, 1998
    Date of Patent: November 9, 1999
    Inventors: David Welch Hart, Brian A. Barnabie
  • Patent number: 5717516
    Abstract: An optical amplification system directs a diffraction-limited signal beam through a series of approximately 90.degree. crossings with a number of non-diffraction-limited pump beams in a photorefractive medium. All of the beams are s-polarized, resulting in an energy transfer from the pumps to the signal beam while leaving the signal beam diffraction-limited. The photorefractive medium is preferably a series of BaTiO.sub.3 :Rh crystals that receive the pump and signal beams through orthogonal faces, with their C-axes at approximately 45.degree. to both beams. A binary tree optical distribution network is used to minimize waveguide splits in forming a large number of pump beams.
    Type: Grant
    Filed: April 4, 1997
    Date of Patent: February 10, 1998
    Assignees: Hughes Electronics, SDL, Inc.
    Inventors: Marvin B. Klein, David M. Pepper, Ronald R. Stephens, Thomas R. O'Meara, David Welch, Robert J. Lang, Jack L. Feinberg, Stuart MacCormack
  • Patent number: 4933301
    Abstract: A method of making semiconductor laser arrays having an impurity disordered pattern of waveguides at least some of which are directly joined at branching junctions. The region near the branching junctions provides a phase boundary condition in which lightwaves propagating in adjacent waveguides are in phase. Using one impurity dose and one disordering depth in a first portion of the pattern and another in a second portion of the pattern provides a combination of strong and weak waveguiding with strong waveguides that eliminate evanescent coupling from occurring at least in the branching junction regions, and with weak guides near one or both end facets permitting evanescent coupling. The evanescent coupling between adjacent weak waveguides preserves the in phase relationship that was established in the Y-junction regions, resulting in a diffraction limited single lobe far field output.
    Type: Grant
    Filed: January 27, 1989
    Date of Patent: June 12, 1990
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: Donald R. Scifres, David Welch, Peter Cross, William Streifer
  • Patent number: 4809288
    Abstract: A semiconductor laser array having a plurality of waveguides at least some of which are directly joined at Y-junctions. The region near the Y-junctions provides a phase boundary condition in which lightwaves propagating in adjacent waveguides are in phase. A combination of strong and weak waveguiding is provided, with strong waveguides that eliminate evanescent coupling from occuring at least in the Y-junction regions, and with weak guides near one or both end facets permitting evanescent coupling. The evanescent coupling between adjacent weak waveguides preserves the in phase relationship that was established in the Y-junction regions, resulting in a diffraction limited single lobe far field output. Alternatively, even without evanescent coupling, the modes can adjust their phases in the weak waveguides, where the propagation constant is less tightly specified by the geometry.
    Type: Grant
    Filed: March 4, 1987
    Date of Patent: February 28, 1989
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: David Welch, Donald R. Scifres, Peter Cross, William Streifer
  • Patent number: 4751711
    Abstract: A phased array laser having a laterally asymmetric variation in the gain or coupling of lasing elements of the array for emission in a single far field lobe. The lasing elements are confined by internal waveguide structuring, periodically spaced current confinement stripes, or by a hybrid of both waveguiding and current confinement. The widths, lengths, depths, or separations of the waveguides or stripes vary laterally across the array to affect the gain or coupling of the lasing elements. Alternate embodiments introduce lateral asymmetry in the active region or other layer thicknesses, doping, mirror facet reflectivities, A1 content of the layers, heat dissipation, or thicknesses of electrical contacts. The laterally asymmetric variations may be linear or nonlinear, monotonically increase from one edge to the other edge, or may be such that the relevant parameter is greatest or least in the center of the array.
    Type: Grant
    Filed: August 16, 1985
    Date of Patent: June 14, 1988
    Assignee: Spectra Diode Laboratories, Inc.
    Inventors: David Welch, Peter Cross, Donald R. Scifres
  • Patent number: 4343867
    Abstract: A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improves the strain characteristics of the wire.
    Type: Grant
    Filed: July 20, 1981
    Date of Patent: August 10, 1982
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Thomas Luhman, Carl J. Klamut, Masaki Suenaga, David Welch
  • Patent number: 4324842
    Abstract: A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improve the strain characteristics of the wire.
    Type: Grant
    Filed: December 19, 1979
    Date of Patent: April 13, 1982
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Thomas Luhman, Carl J. Klamut, Masaki Suenaga, David Welch