Fitting peak seeking method for cavity-length-related demodulation of optical fiber Fabry-Perot sensor

Abstract

Disclosed is a fitting peak seeking method for the cavity-length-related demodulation of an optical fiber Fabry-Perot sensor. The method is used for accurately determining the peak position of a related interference signal in an optical-wedge-type related demodulation system and acquiring the cavity length of the optical fiber Fabry-Perot sensor. The peak seeking process comprises the steps that light intensity distribution information of the related interference signal detected by a CCD linear array is obtained through a sampling circuit, and light intensity and corresponding position information are output through two array modes; firstly, the related interference signal data is preprocessed to remove a base signal, then an upper envelope point of the pre-processed related interference signal is extracted and subjected to Gaussian fitting, the peak position is accurately determined, and the cavity length of the optical fiber Fabry-Perot sensor is calculated. Due to the adoption of the Gaussian fitting method, the resolution limited by the size and number of CCD pixel units is increased, and the accuracy of calculating the cavity length of the optical-wedge-type related demodulation system of the optical fiber Fabry-Perot sensor is improved.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensing, in particular to a peak-fitting method for cavity length correlation demodulation of an optical fiber F-P sensor. Background technique [0002] Due to its light weight, small size, high sensitivity, large dynamic response range and strong anti-electromagnetic interference ability, the optical fiber sensor has become one of the important research directions in the field of optical fiber sensing, especially in the field of strong electromagnetic interference, high temperature and high pressure. Applications in harsh environments such as sensors have incomparable advantages over traditional sensors. The optical wedge demodulation system of fiber-optic sensors mostly uses broadband light sources such as tungsten-halogen lamps, LEDs, and SLDs. Among them, tungsten-halogen lamps and LEDs have larger bandwidths and can generate related interference signals with higher contrast, but the div...

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Problems solved by technology

[0003] Aiming at the problem that the resolution limitation of CCD linear array pixel unit size and the limited bandwidth of broadband light source lead to low contrast of correlation interference signal, the present invention provides a fitting peak-finding method for cavity length correlation demodulation of optical fiber F-P sensor, Improved demodulation accuracy of fiber-optic F-P sensors

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