High-precision and fast optical fiber grating spectrum peak-searching method

Abstract

The invention discloses a high-precision and fast optical fiber grating spectrum peak-searching method. Taking searching a positive peak in the reflection spectrum of a reflection type optical fiber grating as an example, a threshold value which is adopted during peak search is first determined according to the maximum value among a plurality of peak values in the reflection spectrum of the optical fiber grating and the signal-to-noise ratio, whether a wave crest is the reflected crest of the optical fiber grating or the crest generated by noise is then judged according to the width and the shape characteristics of a set reflection spectrum, and the horizontal coordinate values of the start point and the end point of the reflected crest are recorded; finally, a left point and a right point on both sides of the reflected crest of the optical fiber grating, which are 3dB lower than the maximum value, are found, the horizontal coordinate values corresponding to the two points are summed up, the sum is then divided by 2, and thereby the position of the peak value is obtained. When a negative peak in the transmission spectrum of the reflection type optical fiber grating is searched, the method is still applicable as long as the method is simply changed; and the method is also suitable for searching the negative peak of the reflection spectrum of a transmission type optical fiber grating and the positive peak of the transmission spectrum of the transmission type optical fiber grating. The method solves the problems of the conventional method, i.e. low peak-searching precision and high computation load.

Description

technical field [0001] The invention relates to the field of optical fiber grating sensing, in particular to a high-precision and fast peak-finding method for optical fiber grating spectral peaks. Background technique [0002] With the development of optical fiber sensing technology, fiber grating sensors are widely used in civil engineering, aerospace, petrochemical, electric power, medical , shipbuilding industry and other fields have been widely used. When the external temperature or strain on the FBG sensor changes, the central wavelength of the reflection spectrum or transmission spectrum of the FBG will change. Therefore, finding the precise position of the peak-to-peak value of the FBG spectrum is an important part of FBG sensing. The key technology, fast and accurate peak-finding method is a necessary condition to ensure the real-time and accuracy of the fiber grating sensing system. At present, commonly used peak-finding algorithms include Monte Carlo algorithm, d...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a high-precision and fast peak-finding method for fiber grating spectrum peaks applied in fiber-optic grating sensing systems, to realize the precise positioning of the peak-peak positions of fiber grating spectra, and to solve the problem of low peak-finding accuracy in existing peak-finding methods , the problem of large amount of computation

Images