提高光纤F-P应变传感器输出信号质量的方法研究

Study on the Method of Improving EFPI′s Signal Quality

光纤F P应变传感器输出信号质量的好坏直接影响解调精度 从光纤F P应变传感器的基本原理出发 ,针对光纤F P腔内损耗的问题 ,提出了用增加端面反射率的办法来弥补耦合损耗的影响 ;并通过理论分析、计算机仿真和实验对该问题进行了研究 实验表明 ,选用与F P腔固有的最佳反射率匹配的端面镀膜 ,对增加干涉图样的对比度 。

The measurement accuracy of EFPI (Extrinsic Fabry Perot Interferometers) strain sensor is affected by the quality of its output signal. However whatever kind of demodulation algorithm is adopted, a poor interferential pattern with low contrast and low amplitude always leads to a rough measurement result. To address this problem, the signal quality of EFPIs with different end reflectivity was theoretically analyzed in this paper. Computer simulation indicated that the signal quality could be improved by increasing the reflectivity of fiber ends in the F P cavity. This is also experimentally demonstrated by vaporization coating to each fiber end.