基于双长周期光纤光栅边缘滤波的光纤布拉格光栅解调系统

Double-Edged Filter Wavelength Demodulation System for Fiber Bragg Gratings Based on Long Period Fiber Grating

从长周期光纤光栅(LPFG)透射光谱和光纤布拉格光栅(FBG)解调原理角度,详细研究了LPFG透射光谱的边缘滤波特性,提出了一种基于双长周期光纤光栅边缘滤波的FBG解调方案,使其在具有对被测参量变化高度灵敏性特点的同时,对温度、湿度等环境参量具有较好的自补偿性能,并对该方案进行了温度、振动信号监测验证。通过理论和实验验证,该解调方法对静、动态信号具有较好的响应特性,其动态信号的响应带宽约为3kHz,在580,1000,2500Hz的激励频率下,该系统具有较好的响应度和精确度,符合结构健康监测领域对FBG解调的要求,具有广泛的应用前景。

From the angle of the interrogation technology for fiber transmission spectrum of long period fiber grating （LPFG） and the wavelength Bragg gratings （FBGs）, the edged filter double-edged filter wavelength interrogation technology for FBGs is proposed the experiments of temperature and vibration signal monitoring are verified characteristic of LPFGs is studied. A The theoretical model is deduced and The demodulation system, which is repeatedly tested under the excitation frequency of 580, 1000 Hz and 2500 Hz, respectively, shows broad dynamic frequency band of 3 kHz, fast response time and high accuracy, with the extensive application prospects.