Strain sensing system based on ultra short FBG (fiber bragg grating) spectrum linear region

Abstract

The invention discloses a strain sensing system based on an ultra short FBG (fiber bragg grating) spectrum linear region, which comprises a frequency stabilized laser, a circulator, an ultra short FBGand a photodiode, wherein one end of the circulator is connected with one end of the frequency stabilized laser, and the other end of the circulator is connected with the ultra short FBG; the photodiode is used for receiving the reflected light power after a laser beam reflected back by the ultra short FBG passes through the circulator; the frequency stabilized laser is an 8164A tunable laser light source, the maximum output power is 8dBm, the laser line width is less than 5pm, and the wavelength stability is less than 1pm. According to the strain sensing system based on the ultra short FBG spectrum linear region, light power reflected by an edge linear region of the ultra short FBG of the laser beam outputted by the frequency stabilized laser is used for demodulation, the structure is simple, the power consumption is low, the ultra short FBG is adopted as a sensing element, the problem of chirp generation during a packaging process due to a long gate area can be avoided, and high spatial resolution measurement can be realized.

Description

technical field [0001] The invention relates to the technical field of fiber grating sensing, in particular to a strain sensing system based on an ultrashort FBG spectral linear region. Background technique [0002] Fiber Bragg grating (FBG) sensing technology has advantages over traditional electrical sensors such as wavelength coding, anti-electromagnetic interference, little interference to the measured object, and is easy to embed in engineering structures. A major research hotspot. And it is widely used in biomedicine, flight control, structure monitoring, deep sea perception and other fields. [0003] In order to ensure a narrow reflection spectrum (generally less than 0.2nm) for ordinary uniform fiber gratings, the length of the grating generally needs to be on the order of centimeters. For the demodulation method of traditional wavelength detection, this narrow linewidth spectral characteristic of fiber Bragg grating is very important, which helps to achieve high m...

AI Technical Summary

Problems solved by technology

[0006] The present invention aims to solve the problem that the traditional fiber grating is not suitable for gradient field measurement and easy to generate chirp in the packaging process due to its long grating region, and provides a sensing and demodulation system based on the linear region of the ultra-short fiber grating spectrum

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