【作者】 夏历； 司马朝坦； 鲁平； 孙琪真； 徐军； 刘海； 刘德明；

【Author】 XIALi;SIMAChao-tan;LUPing;SUN Qi-zhen;XUJun;LIU Hai;LIU Deming;Next Generation Internet Access system National Engineering Laboratory, Huazhong University of Science and Technology;

【机构】 下一代互联网接入系统国家工程实验室华中科技大学；

【摘要】 本文提出了一种基于光纤布拉格光栅(FBGs)微波检测的准分布式传感技术。这些FBGs都是完全相同的,具有低反射率和高反射带宽。微波信号常常用于解决FBGs沿着光纤方向的定位和反射强度问题;由于在探测中采用与检测谱线想匹配的光学宽带滤波器,使得每个FBG的反射强度都可以被由传感参数所引入的波长变化效应所调制。而微波响应的相对幅度变化(RAC)则由FBGs反射强度所决定。我们采用6个相同的FBG设计搭建了验证性试验来进行压力传感检测;测试结果表明,可以实现0.0452%RAC/u?很高的压力检测敏感性,以及达到2000u?的检测范围;通过IFFT算法的解调制计算,传感位置可以实现位置精度为10.2cm的精确定位。更多还原

【Abstract】 We present a quasi-distributed fiber sensing technique by monitoring the microwave responses through the reflections of the fiber Bragg gratings(FBGs). These FBGs are all identical and specially fabricated with the low reflectivity and the broad reflection bandwidth. The microwave signals are used to resolve the positions and the reflected intensities from FBGs along the optical fiber. The reflected intensity of each FBG can be modulated through the wavelength shift induced by the sensing parameter, since the optical bandpass filter with the matched spectrum is adopted in the detection. The relative amplitude change(RAC) of the microwave responses are determined by the change of reflected intensities from FBGs. We demonstrate a proof-of-concept experiment for the strain sensing using 6 identical FBGs. The experimental measurements show that a high strain sensing sensitivity of 0.0452 %RAC/με is achieved within the measured range of 2000με. The sensing positions also can be accurately located from the demodulation figure through IFFT algorithm with the locating resolution of about 10.2 cm.更多还原