啁啾光栅解调的准分布式光纤Bragg光栅传感器

Quasi-distributed fiber Bragg grating sensor using the demodulation of chirped grating

为了提高光纤Bragg光栅（FBG）的应用范围,提出一种线性啁啾光栅（CFBG）解调的准分布式FBG传感系统。利用波导理论分析了CFBG特性;利用传输矩阵法推导了CFBG反射谱模型及波长与相位延迟的关系,并给出了相位延迟曲线。实验表明：所设计的系统应变测量范围为0-2 000με,温度测量范围为0-80℃;相位变化与被测信号成线性关系,拟合度分别为0.990和0.998,能满足工程应用的要求。

A quasi-distributed fiber Bragg grating（FBG） sensing system based on linear by chirped grating is proposed in this paper,aiming at improving the application range of fiber Bragg grating.The characteristics of chirped grating are analyzed using waveguide theory,the reflection spectrum model and the wavelength dependence of the phase group-delay of chirped grating are derived by means of transfer matrix method,and the phase delay curve is obtained.The experimental results show that the strain measurement range is 0-2 000 με and the temperature measurement range is 0-80 ℃.The phase shift and the strain as well as the temperature have good linear relationship,and the fitting linearities are 0.99 and 0.998,respectively.This technique can meet the requirements of engineering application.