Shaanxi Key Lab of MEMS/NEMS, Northwestern Polytechnical University, Xi'an 710072, China.
Key Lab of Micro/Nano Systems for Aerospace, Ministry of Education, Northwestern Polytechnical University, Xi'an 710072, China.
Sensors (Basel). 2019 Sep 22;19(19):4097. doi: 10.3390/s19194097.
This study presents an extrinsic Fabry-Perot interferometric (EFPI) fiber-optic strain sensor with a very short cavity. The sensor consists of two vertically cut standard single-mode fibers (SMFs) and a glass capillary with a length of several centimeters. The two SMFs penetrate into the glass capillary and are fixed at its two ends with the use of ultraviolet (UV) curable adhesives. Based on the use of the lengthy glass capillary sensitive element, the strain sensitivity can be greatly enhanced. Experiments showed that the microcavity EPFI strain sensor with initial cavity lengths of 20 μm, 30 μm, and 40 μm, and a capillary length of 40 mm, can yield respective cavity length-strain sensitivities of 15.928 nm/με, 25.281 nm/με, and 40.178 nm/με, while its linearity was very close to unity for strain measurements spanning a range in excess of 3500 με. Furthermore, the strain-temperature cross-sensitivity was extremely low.
本研究提出了一种具有非常短腔的外部法布里-珀罗干涉（EFPI）光纤应变传感器。该传感器由两根垂直切割的标准单模光纤（SMF）和一根长数厘米的玻璃毛细管组成。两根 SMF 插入玻璃毛细管中，并使用紫外线（UV）固化胶固定在其两端。基于使用长玻璃毛细管敏感元件，应变灵敏度可以大大提高。实验表明，初始腔长为 20μm、30μm 和 40μm，毛细管长度为 40mm 的微腔 EPFI 应变传感器，其腔长-应变灵敏度分别为 15.928nm/με、25.281nm/με 和 40.178nm/με，而其线性度对于超过 3500με 的应变测量非常接近 1。此外，应变-温度交叉灵敏度非常低。
