System and method for determination of the reflection wavelength of multiple low-reflectivity bragg gratings in a sensing optical fiber
First Claim
1. A system for determining a reflection wavelength of multiple low-reflectivity Bragg gratings in a sensing optical fiber having a broadband reflector and a plurality of the Bragg gratings at different distances from the broadband reflector along a length of the sensing optical fiber, the system comprising:
- a source laser coupled to the sensing optical fiber;
an optical detector coupled to the sensing optical fiber and configured to detect a reflected signal from the sensing optical fiber;
a plurality of frequency generators, each frequency generator configured to generate a signal having a frequency corresponding to an interferometer frequency of a different one of the plurality of Bragg gratings;
a plurality of demodulation elements, each demodulation element coupled to the optical detector and to a different one of the plurality of frequency generators, each demodulation element configured to combine the signal produced by a different one of the plurality of frequency generators with the detected signal from the sensing optical fiber;
a plurality of peak detectors, each peak detector coupled to a different one of the demodulation elements and configured to detect a peak of the combined signal from a different one of the demodulation elements; and
a laser wavenumber detection element coupled to the peak detectors and configured to determine a wavenumber of the laser when any of the peak detectors detects a peak.
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Accused Products
Abstract
A system and method for determining a reflection wavelength of multiple Bragg gratings in a sensing optical fiber comprise: (1) a source laser; (2) an optical detector configured to detect a reflected signal from the sensing optical fiber; (3) a plurality of frequency generators configured to generate a signal having a frequency corresponding to an interferometer frequency of a different one of the plurality of Bragg gratings; (4) a plurality of demodulation elements, each demodulation element configured to combine the signal produced by a different one of the plurality of frequency generators with the detected signal from the sensing optical fiber; (5) a plurality of peak detectors, each peak detector configured to detect a peak of the combined signal from a different one of the demodulation elements; and (6) a laser wavenumber detection element configured to determine a wavenumber of the laser when any of the peak detectors detects a peak.
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Citations
14 Claims
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1. A system for determining a reflection wavelength of multiple low-reflectivity Bragg gratings in a sensing optical fiber having a broadband reflector and a plurality of the Bragg gratings at different distances from the broadband reflector along a length of the sensing optical fiber, the system comprising:
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a source laser coupled to the sensing optical fiber; an optical detector coupled to the sensing optical fiber and configured to detect a reflected signal from the sensing optical fiber; a plurality of frequency generators, each frequency generator configured to generate a signal having a frequency corresponding to an interferometer frequency of a different one of the plurality of Bragg gratings; a plurality of demodulation elements, each demodulation element coupled to the optical detector and to a different one of the plurality of frequency generators, each demodulation element configured to combine the signal produced by a different one of the plurality of frequency generators with the detected signal from the sensing optical fiber; a plurality of peak detectors, each peak detector coupled to a different one of the demodulation elements and configured to detect a peak of the combined signal from a different one of the demodulation elements; and a laser wavenumber detection element coupled to the peak detectors and configured to determine a wavenumber of the laser when any of the peak detectors detects a peak. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for determining a reflection wavelength of multiple low-reflectivity Bragg gratings in a sensing optical fiber having a broadband reflector and a plurality of the Bragg gratings at different distances from the broadband reflector along a length of the sensing optical fiber, the method comprising the steps of:
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providing a source laser coupled to the sensing optical cable; providing an optical detector coupled to the sensing optical fiber and configured to detect a reflected signal from the sensing optical fiber; providing a plurality of frequency generators, each frequency generator configured to generate a signal having a frequency corresponding to an interferometer frequency of a different one of the plurality of Bragg gratings; providing a plurality of demodulation elements, each demodulation element coupled to the optical detector and to a different one of the plurality of frequency generators, each demodulation element configured to combine the signal produced by a different one of the plurality of frequency generators with the detected signal from the sensing optical fiber; providing a plurality of peak detectors, each peak detector coupled to a different one of the demodulation elements and configured to detect a peak of the combined signal from a different one of the demodulation elements; and providing a laser wavenumber detection element coupled to the peak detectors and configured to determine a wavenumber of the laser when any of the peak detectors detects a peak. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification