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US 11,698,277 B2Granted
Method and system for determining grating perturbation by modulated light
AssigneeAriel Scientific Innovations Ltd.
InventorsShmuel Sternklar, Ziv Glasser
Life of this patent
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Abstract
A method of determining perturbation of a grating formed in an optical fiber, comprises: modulating and transmitting a light beam through the optical fiber, measuring at least one phase shift in a modulation of light reflected off the grating, and determining the perturbation of the grating based on the phase shift(s).
Claims30
A method of determining perturbation of a grating formed in an optical fiber, the method comprising:
- modulating and transmitting a light beam through the optical fiber, dispersing light reflected off the grating, measuring at least one phase shift in a modulation of said reflected light, and determining the perturbation of the grating based on said at least one phase shift;
- wherein said dispersing is prior to said measurement of said at least one phase shift;
- wherein the optical fiber is formed with a plurality of gratings, wherein at least two of said gratings are characterized by different Bragg wavelengths, wherein said measurement of said at least one phase shift is characterized by a predetermined phase resolution, and said dispersing is characterized by a predetermined dispersion parameter describing pulse broadening per unit wavelength, and wherein a frequency of said modulating is at least a ratio between said phase resolution and a multiplication of said dispersion parameter by a predetermined spectral resolution threshold.
A system for determining perturbation of a grating formed in an optical fiber, the system comprising:
- an optical modulation system for modulating a light beam;
- an optical coupler for coupling said light beam into the optical fiber and receiving light reflected off the grating;
- and
- an optical and electrical analysis system configured for measuring at least one phase shift in a modulation of light reflected off the grating, and determining the perturbation of said grating based on said at least one phase shift;
- wherein said optical and electrical analysis system comprises:
- a dispersive optical device configured for dispersing said reflected light beam prior to said measurement of said at least one phase shift;
- and
- a signal processing system configured for measuring said at least one phase shift at a predetermined phase resolution, wherein said dispersive optical device is configured for effecting dispersing according to a predetermined dispersion parameter describing pulse broadening per unit wavelength, and wherein said optical modulation system is configured for modulating said light beam at a frequency which is at least a ratio between said phase resolution and a multiplication of said dispersion parameter by a predetermined spectral resolution threshold.
5 more elements
A sensor system, comprising:
- an optical modulation system for modulating a light beam;
- an optical coupler for coupling said light beam into a fiber formed with a grating and receiving light reflected off the grating;
- and
- an optical and electrical analysis system configured for measuring at least one phase shift in a modulation of light reflected off the grating, and determining at least one physical quantity effecting a perturbation of said grating;
- wherein said optical and electrical analysis system comprises:
- a dispersive optical device configured for dispersing said reflected light beam prior to said measurement of said at least one phase shift;
- and
- a signal processing system configured for measuring said at least one phase shift at a predetermined phase resolution, wherein said dispersive optical device is configured for effecting dispersing according to a predetermined dispersion parameter describing pulse broadening per unit wavelength, and wherein said optical modulation system is configured for modulating said light beam at a frequency which is at least a ratio between said phase resolution and a multiplication of said dispersion parameter by a predetermined spectral resolution threshold.
5 more elements
A method of determining perturbation of a plurality of gratings formed in an optical fiber, the method comprising:
- modulating and transmitting a light beam through the optical fiber, wherein said modulating comprises scanning a frequency of said modulation over a plurality of modulation frequencies;
- dispersing light reflected off the gratings;
- measuring a modulation phase shift and modulation magnitude of said reflected light for each modulation frequency;
- and
- determining perturbation of at least two of the gratings based on said measured modulation phase shifts and measured modulation magnitudes;
- wherein said dispersing is prior to said measurement of said at least one phase shift;
- wherein at least two of said gratings are characterized by different Bragg wavelengths, wherein said measurement of said at least one phase shift is characterized by a predetermined phase resolution, and said dispersing is characterized by a predetermined dispersion parameter describing pulse broadening per unit wavelength, and wherein a frequency of said modulating is at least a ratio between said phase resolution and a multiplication of said dispersion parameter by a predetermined spectral resolution threshold.
4 more elements
A method of determining perturbation of a grating formed in an optical fiber, the method comprising:
- modulating and transmitting a light beam through the optical fiber, dispersing light reflected off the grating, measuring at least one phase shift in a modulation of said reflected light, and determining the perturbation of the grating based on said at least one phase shift;
- wherein said reflected light beam prior to said measurement of said at least one phase shift;
- wherein the optical fiber is formed with a plurality of gratings, wherein at least two of said gratings are characterized by different Bragg wavelengths, wherein said dispersing is characterized by a dispersion coefficient, wherein the method comprises varying a value of said coefficient over a plurality of dispersion coefficient values, measuring a modulation phase shift and modulation magnitude of light reflected off the grating for each value of said dispersion coefficient, and determining an individual optical wavelength or optical frequency shift for each of said at least two gratings, based on said measured modulation phase shifts and measured modulation magnitudes.
A system for determining perturbation of a grating formed in an optical fiber, the system comprising:
- an optical modulation system for modulating a light beam;
- an optical coupler for coupling said light beam into the optical fiber and receiving light reflected off the grating;
- and
- an optical and electrical analysis system configured for measuring at least one phase shift in a modulation of light reflected off the grating, and determining the perturbation of said grating based on said at least one phase shift;
- wherein the optical fiber is formed with a plurality of gratings, wherein at least two of said gratings are characterized by different Bragg wavelengths;
- wherein said optical and electrical analysis system comprises a dispersive optical device configured for dispersing said reflected light beam prior to said measurement of said at least one phase shift, wherein said dispersing is characterized by a dispersion coefficient, wherein a value of said coefficient is varied over a plurality of dispersion coefficient values;
- and
- wherein said optical and electrical analysis system is configured for measuring a modulation phase shift and modulation magnitude of light reflected off the grating for each value of said dispersion coefficient, and determining an individual optical wavelength or optical frequency shift for each of said at least two gratings, based on said measured modulation phase shifts and measured modulation magnitudes.
5 more elements
A sensor system, comprising:
- an optical modulation system for modulating a light beam;
- an optical coupler for coupling said light beam into a fiber formed with a plurality of gratings and receiving light reflected off the gratings;
- and
- an optical and electrical analysis system configured for measuring at least one phase shift in a modulation of light reflected off the grating, and determining at least one physical quantity effecting a perturbation of said grating;
- wherein said optical and electrical analysis system comprises a dispersive optical device configured for dispersing said reflected light beam prior to said measurement of said at least one phase shift, wherein said dispersing is characterized by a dispersion coefficient, wherein a value of said coefficient is varied over a plurality of dispersion coefficient values;
- and
- wherein said optical and electrical analysis system is configured for measuring a modulation phase shift and modulation magnitude of light reflected off the grating for each value of said dispersion coefficient, and determining an individual optical wavelength or optical frequency shift for each of said at least two gratings, based on said measured modulation phase shifts and measured modulation magnitudes.
4 more elements
A method of determining perturbation of a plurality of gratings formed in an optical fiber, the method comprising:
- modulating and transmitting a light beam through the optical fiber, wherein said modulating comprises scanning a frequency of said modulation over a plurality of modulation frequencies;
- dispersing light reflected off the gratings;
- measuring a modulation phase shift and modulation magnitude of said reflected light for each modulation frequency;
- and
- determining perturbation of at least two of the gratings based on said measured modulation phase shifts and measured modulation magnitudes;
- wherein said dispersing is prior to said measurement of said at least one phase shift;
- wherein said dispersing is characterized by a dispersion coefficient, wherein the method comprises varying a value of said coefficient over a plurality of dispersion coefficient values, measuring a modulation phase shift and modulation magnitude of light reflected off the grating for each value of said dispersion coefficient, and determining an individual optical wavelength or optical frequency shift for each of said plurality of gratings, based on said measured modulation phase shifts and measured modulation magnitudes.
4 more elements
Dependencies are inferred from the claim text.