Patents by Inventor Mark Froggatt

Mark Froggatt 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: 8004686
    Abstract: An optical device under test (DUT) is interferometrically measured. The DUT can include one or more of an optical fiber, an optical component, or an optical system. First interference pattern data for the DUT is obtained for a first path to the DUT, and second interference pattern data for the DUT is obtained for a second somewhat longer path to the DUT. Because of that longer length, the second interference pattern data is delayed in time from the first interference pattern data. A time varying component of the DUT interference pattern data is then identified from the first and second interference pattern data. The identified time varying component is used to modify the first or the second interference pattern data to compensate for the time-varying phase caused by vibrations, etc. One or more optical characteristics of the DUT may then be determined based on the modified interference pattern data.
    Type: Grant
    Filed: December 13, 2005
    Date of Patent: August 23, 2011
    Assignee: Luna Innovations Inc.
    Inventors: Mark Froggatt, Dawn K. Gifford
  • Patent number: 7948633
    Abstract: An optical device under test (DUT) is interferometrically measured. The DUT can include one or more of an optical fiber, an optical component, or an optical system. First interference pattern data for the DUT is obtained for a first path to the DUT, and second interference pattern data for the DUT is obtained for a second somewhat longer path to the DUT. Because of that longer length, the second interference pattern data is delayed in time from the first interference pattern data. A time varying component of the DUT interference pattern data is then identified from the first and second interference pattern data. The identified time varying component is used to modify the first or the second interference pattern data to compensate for the time-varying phase caused by vibrations, etc. One or more optical characteristics of the DUT may then be determined based on the modified interference pattern data.
    Type: Grant
    Filed: August 23, 2010
    Date of Patent: May 24, 2011
    Assignee: Luna Innovations Inc.
    Inventors: Mark Froggatt, Dawn K. Gifford
  • Publication number: 20100321702
    Abstract: An optical device under test (DUT) is interferometrically measured. The DUT can include one or more of an optical fiber, an optical component, or an optical system. First interference pattern data for the DUT is obtained for a first path to the DUT, and second interference pattern data for the DUT is obtained for a second somewhat longer path to the DUT. Because of that longer length, the second interference pattern data is delayed in time from the first interference pattern data. A time varying component of the DUT interference pattern data is then identified from the first and second interference pattern data. The identified time varying component is used to modify the first or the second interference pattern data to compensate for the time-varying phase caused by vibrations, etc. One or more optical characteristics of the DUT may then be determined based on the modified interference pattern data.
    Type: Application
    Filed: August 23, 2010
    Publication date: December 23, 2010
    Applicant: Luna Innovations Inc.
    Inventors: Mark Froggatt, Dawn K. Gifford
  • Patent number: 7633607
    Abstract: Measurement equipment may be calibrated using two different calibration paths. An initial calibration is performed using a calibration path in which an optical element may be coupled for testing after the initial calibration. Once the initial calibration has been performed and the optical element operatively-connected in the main path for testing, one or more re-calibrations occur using another calibration path. The optical element being tested need not be de-coupled during the re-calibration. Each calibration operation produces error correction matrices which are used to correct the measurement matrix generated by the test equipment for the optical element being tested.
    Type: Grant
    Filed: September 1, 2004
    Date of Patent: December 15, 2009
    Assignee: Luna Innovations Incorporated
    Inventor: Mark Froggatt
  • Publication number: 20090103100
    Abstract: An optical device under test (DUT) is interferometrically measured. The DUT can include one or more of an optical fiber, an optical component, or an optical system. First interference pattern data for the DUT is obtained for a first path to the DUT, and second interference pattern data for the DUT is obtained for a second somewhat longer path to the DUT. Because of that longer length, the second interference pattern data is delayed in time from the first interference pattern data. A time varying component of the DUT interference pattern data is then identified from the first and second interference pattern data. The identified time varying component is used to modify the first or the second interference pattern data to compensate for the time-varying phase caused by vibrations, etc. One or more optical characteristics of the DUT may then be determined based on the modified interference pattern data.
    Type: Application
    Filed: December 13, 2005
    Publication date: April 23, 2009
    Applicant: LUNA INNOVATIONS INC.
    Inventors: Mark Froggatt, Dawn K. Gifford
  • Patent number: 7515276
    Abstract: The technology described here enables the use of an inexpensive laser to measure an interferometric response of an optical device under test (DUT) at reflection lengths significantly greater than the coherence length of the laser. This is particularly beneficial in practical interferometric applications where cost is a concern. In other words, inexpensive lasers having shorter coherence lengths may be used to achieve very high interferometric measurements at longer DUT reflection lengths. The technology also enables the use of such inexpensive lasers to measure Rayleigh scatter in commercial-grade, single-mode optical fiber.
    Type: Grant
    Filed: July 18, 2007
    Date of Patent: April 7, 2009
    Assignee: Luna Innovations Incorporated
    Inventors: Mark Froggatt, Ryan J. Seeley, Dawn K. Gifford
  • Publication number: 20080024785
    Abstract: The technology described here enables the use of an inexpensive laser to measure an interferometric response of an optical device under test (DUT) at reflection lengths significantly greater than the coherence length of the laser. This is particularly beneficial in practical interferometric applications where cost is a concern. In other words, inexpensive lasers having shorter coherence lengths may be used to achieve very high interferometric measurements at longer DUT reflection lengths. The technology also enables the use of such inexpensive lasers to measure Rayleigh scatter in commercial-grade, single-mode optical fiber.
    Type: Application
    Filed: July 18, 2007
    Publication date: January 31, 2008
    Applicant: Luna Innovations Incorporated
    Inventors: Mark Froggatt, Ryan Seeley, Dawn Gifford
  • Publication number: 20080007718
    Abstract: A fiber optic measurement device including an optical frequency domain reflectometer (10) performs polarization diversity detection without using a polarizing beam splitter.
    Type: Application
    Filed: July 8, 2003
    Publication date: January 10, 2008
    Inventors: Mark Froggatt, Brian Soller, Matthew Wolfe
  • Publication number: 20080002187
    Abstract: A portion of a polarization maintaining (PM) optical fiber having two polarization states is analyzed. First and second spectral responses of the PM fiber portion are determined. In a preferred implementation, the spectral responses are determined using Optical Frequency Domain Reflectometry (OFDR). Each polarization state of the PM fiber portion has a corresponding spectral component in the first spectral response. First and second spectral analyses of the PM fiber portion are performed using the first and second spectral responses. Based on those spectral analyses of the PM fiber portion, a first physical characteristic affecting the PM fiber portion is determined that is distinct from a second different physical characteristic affecting the fiber portion. Example physical characteristics include temperature and strain. An output signal related to the first physical characteristics affecting the fiber portion is provided, e.g., for display, further processing, etc.
    Type: Application
    Filed: June 7, 2007
    Publication date: January 3, 2008
    Inventor: Mark Froggatt
  • Publication number: 20070171399
    Abstract: Measurement equipment may be calibrated using two different calibration paths. An initial calibration is performed using a calibration path in which an optical element may be coupled for testing after the initial calibration. Once the initial calibration has been performed and the optical element operatively-connected in the main path for testing, one or more re-calibrations occur using another calibration path. The optical element being tested need not be de-coupled during the re-calibration. Each calibration operation produces error correction matrices which are used to correct the measurement matrix generated by the test equipment for the optical element being tested.
    Type: Application
    Filed: September 1, 2004
    Publication date: July 26, 2007
    Inventor: Mark Froggatt
  • Publication number: 20070065077
    Abstract: The present invention is directed toward a fiber optic position and shape sensing device and the method of use. The device comprises an optical fiber means. The optical fiber means comprises either at least two single core optical fibers or a multicore optical fiber having at least two fiber cores. In either case, the fiber cores are spaced apart such that mode coupling between the fiber cores is minimized. An array of fiber Bragg gratings are disposed within each fiber core and a frequency domain reflectometer is positioned in an operable relationship to the optical fiber means. In use, the device is affixed to an object. Strain on the optical fiber is measured and the strain measurements correlated to local bend measurements. Local bend measurements are integrated to determine position and/or shape of the object.
    Type: Application
    Filed: September 26, 2006
    Publication date: March 22, 2007
    Applicant: Luna Innovations Incorporated
    Inventors: Brooks Childers, Dawn Gifford, Roger Duncan, Matthew Raum, Michael Vercellino, Mark Froggatt
  • Publication number: 20060204165
    Abstract: Light is coupled into two polarization modes of a waveguide, e.g., an optical fiber. The spectral response of Rayleigh backscatter in the waveguide segment for the two polarization modes is measured, e.g., using OFDR, OTDR, OLCR, etc. The autocorrelation of the spectral response is calculated. The spectral (wavelength) shift from a main autocorrelation peak to a side autocorrelation peak, corresponding to one of the two polarization modes of the waveguide segment, is determined. The spectral shift, corresponding to a beat length of the waveguide segment, is multiplied by an average index of refraction to determine a birefringence of the waveguide segment.
    Type: Application
    Filed: March 9, 2006
    Publication date: September 14, 2006
    Applicant: Luna Innovations Incorporated
    Inventor: Mark Froggatt
  • Publication number: 20060164627
    Abstract: A fiber optic measurement device including an optical frequency domain reflectometer (10) performs polarization diversity detection without using a polarizing beam splitter.
    Type: Application
    Filed: July 8, 2003
    Publication date: July 27, 2006
    Inventors: Mark Froggatt, Brian Soller, Matthew Wolfe
  • Publication number: 20060033927
    Abstract: A heterodyne optical signal analyzer (HOSA) permits accurate reconstruction of an optical input signal (Es) in the time domain. In one embodiment, a vector representation of the light is used to account for two polarization states of the optical signal. The components of a heterodyne optical signal analyzer (10), including optical couplers (12), all have errors and offsets. For example, optical power detectors (16) are very sensitive to changes in polarization of the optical signal (Es) and of the reference signal (Er). Several HOSA calibration procedures including detector calibration, vector calibration, and reference signal calibration are described.
    Type: Application
    Filed: July 8, 2003
    Publication date: February 16, 2006
    Inventors: Mark Froggatt, Brian Soller, Matthew Wolfe
  • Publication number: 20050219512
    Abstract: Complex data is obtained from OFDR backscatter measurements for an optical device under test (DUT). That complex scatter pattern data may be used along with a previously-determined fiber segment pattern to identify the fiber segment within the DUT, even when the DUT is an optical network DUT that includes multiple fibers coupled to perform one or more functions. In other non-limiting example applications, the OFDR scatter pattern data can be used to identify where in the DUT a loss occurred and where in the DUT a temperature change occurred.
    Type: Application
    Filed: February 23, 2005
    Publication date: October 6, 2005
    Applicant: Luna Technologies
    Inventors: Mark Froggatt, Brian Soller
  • Publication number: 20050088661
    Abstract: In order to characterize the optical characteristics of a device, a source of light having a variable frequency with a polarization state which varies linearly with frequency is provided as an input to the device under test. The input light is also passed through a known reference path and is added to the light output from the device under test in a beam combiner. The combined light for the frequencies of interest is split into two orthogonal polarizations which are then detected in a spectral acquisition apparatus and supplied to a microprocessor. The spectral measurements are digitized and curve-fitted to provide optical power versus optical frequency curves. Fourier transforms of each of the curves are calculated by the microprocessor. From the Fourier transforms, the four arrays of constants are calculated for the Jones matrix characterizing the device under test.
    Type: Application
    Filed: November 18, 2004
    Publication date: April 28, 2005
    Applicant: Luna Technologies
    Inventor: Mark Froggatt