A method and apparatus for reducing crosstalk between sensors in an inline Fabry-Perot (FP) sensor array. The inline FP sensor array comprises a plurality of fiber Bragg gratings arranged periodically along an optical fiber. The sensors are formed between each of the Bragg gratings. A light source provides multiplexed pulses as interrogation pulses for the array. The light pulses are applied to one end of the sensor array and a light detector detects reflected pulses. The detected pulses comprise a composite of reflections from all the Bragg gratings along the fiber. The apparatus processes the detected signals using an inverse scattering algorithm to detect an accurate phase response from each of the Bragg sensors while reducing crosstalk from other Bragg sensors within the array. One form of inverse scattering algorithm is a layer-peeling algorithm.
A method and apparatus for reducing crosstalk between sensors in an inline Fabry-Perot (FP) sensor array. The inline FP sensor array comprises a plurality of fiber Bragg gratings arranged periodically along an optical fiber. The sensors are formed between each of the Bragg gratings. A light source provides multiplexed pulses as interrogation pulses for the array. The light pulses are applied to one end of the sensor array and a light detector detects reflected pulses. The detected pulses comprise a composite of reflections from all the Bragg gratings along the fiber. The apparatus processes the detected signals using an inverse scattering algorithm to detect an accurate phase response from each of the Bragg sensors while reducing crosstalk from other Bragg sensors within the array. One form of inverse scattering algorithm is a layer-peeling algorithm.
A method and apparatus for producing depolarized light that is useful in forming interrogation signals for an optical sensor array and demodulator having reduced polarization-induced fading and phase noise. The depolarized light is produced by splitting a light beam, delaying a first orthogonal component of the light beam with respect to a second orthogonal component of the light beam using a predefined delay, while maintaining the polarization of the first orthogonal component and the polarization of the second orthogonal component. The delayed light beams are combined to produce a depolarized light beam by selecting a predefined delay that causes an interference signal having a delay equal to the predefined delay to be suppressed during a demodulation process.
A method and apparatus that uses specific source modulation and detectors to detect a response that carries information about a system response matrix associated with each sensor in a interferometric sensor array and extracting a sensor response in a manner that eliminates polarization-induced signal fading and that is insensitive to lead fiber birefringence fluctuations.
A method and apparatus for reducing crosstalk between sensors in an inline Fabry-Perot (FP) sensor array. The inline FP sensor array comprises a plurality of fiber Bragg gratings arranged periodically along an optical fiber. The sensors are formed between each of the Bragg gratings. A light source provides multiplexed pulses as interrogation pulses for the array. The light pulses are applied to one end of the sensor array and a light detector detects reflected pulses. The detected pulses comprise a composite of reflections from all the Bragg gratings along the fiber. The apparatus processes the detected signals using an inverse scattering algorithm to detect an accurate phase response from each of the Bragg sensors while reducing crosstalk from other Bragg sensors within the array. One form of inverse scattering algorithm is a layer-peeling algorithm.
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