FBG旁瓣对复用解调的影响及旁瓣抑制方法

基于FBG应变传感器的解调原理，分析了光纤布拉格光栅串联复用时反射谱旁瓣对解调结果的影响，通过理论推导及模拟仿真，发现FBG传感器性能蜕化时存在反射谱的带宽变大、峰值降低以及旁瓣增大等现象，并且详细分析了反射谱旁瓣以及链路连接损耗对FBG复用解调结果产生的影响，针对这个问题，提出了利用浮动解调阈值以及抑制反射谱旁瓣的解决方法，最后，通过实验证实了相关理论的正确性与方法的可行性，极大地提高了应变测量结果的准确性。

Affects of sidelobes of FBG on multiplexing demodulation and suppression methods for sidelobes

Based on the demodulating theory of FBG, the demodulation affection of reflection sidelobe on the fiber Bragg grating strain sensor is analyzed. The phenomenon that bandwidth of reflection spectrum largens, the peak value falls, and the reflection sidelobe augment when the performance of FBG sensor degenerates by theoretical deduction and simulation. Then the effect of reflection sidelobe and the loss of link connection on the FBG multiplex demodulation result are analyzed in detailed, aiming at the problem that the solution of using floating demodulation threshold and restraining reflection sidelobe are presented. The experimental results show that, the theory is validity and the method is feasibility, and the accuracy of measuring strain result is greatly improved.