Liu Qingwen, Tokunaga Tomochika, He Zuyuan
Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Opt Express. 2011 Oct 10;19(21):20214-23. doi: 10.1364/OE.19.020214.
Aiming at realizing a static strain sensor of nano-strain resolution, which is required in most geophysical applications, this paper presents a thorough analysis on the strain resolution of a fiber Bragg grating (FBG) static strain sensor interrogated with a narrow linewidth tunable laser. The main noise sources of the sensor are discussed, and the strain resolution is deduced with a cross-correlation algorithm. The theoretical prediction agrees well with our experimental result, and the analysis is further validated by numerical simulations. Based on the analysis, the paper provides the guidelines for optimizing this type of sensor to realize ultra-high resolution. It is shown that with properly designed FBGs and interrogation systems, nano static strain resolution can be realized, as we recently demonstrated in experiment.
针对大多数地球物理应用中所需的实现具有纳米应变分辨率的静态应变传感器，本文对采用窄线宽可调谐激光器询问的光纤布拉格光栅（FBG）静态应变传感器的应变分辨率进行了全面分析。讨论了该传感器的主要噪声源，并采用互相关算法推导出应变分辨率。理论预测与我们的实验结果吻合良好，且该分析通过数值模拟得到了进一步验证。基于该分析，本文给出了优化此类传感器以实现超高分辨率的指导原则。结果表明，通过合理设计FBG和询问系统，可以实现纳米静态应变分辨率，正如我们最近在实验中所展示的那样。
