基于双包层大模场光纤的Fabry-Perot应变传感器

Optical Fiber Fabry-Perot Strain Sensor Based on LMA-DCF

提出了一种通过化学腐蚀对双包层大模场光纤进行加工,并结合放电熔接工艺制备光纤法布里-珀罗(Fabry-Perot,F-P)传感器的方法。将尺寸为20/125μm的双包层大模场光纤端面切平后在浓度为40%氢氟酸中浸泡20 min使光纤端面形成凹槽,再与端面切平的HI-1060光纤进行熔接,在熔接点处形成气泡,构成全光纤F-P腔结构,反射谱波长周期为9 nm,条纹对比度达到9. 55 dB。采用等强度梁对传感器的应变特性进行测试与分析,在0~350με范围内分别进行加载与卸载实验,波长灵敏度大于2. 88 pm/με,线性度高于0. 99。

Large-mode-area double-clad fiber fabricated by chemical corrosion was proposed The method of fabricating Fabry-Perot(F-P)sensor was combined with discharge welding technology.The end face of large-mode-area double-clad fiber with the size of 20/125μm was immersed in hydrofluoric acid with concentration of 40%for 20 min to form a groove.Then it was spliced with HI-1060 whose end face was plane.Bubbles were formed at the fusion junction to form the whole fiber F-P cavity structure.The reflectance spectrum has a wavelength cycle of 9 nm and a stripe contrast of 9.55 dB.The strain characteristic of the sensor was tested and analyzed by the equal strength beam.In the load and upload test range of 0~350με,the sensitivity was more than 2.88 pm/μεand linearity was 0.99 dB in the test range of 3~350με.