Simulation and experimental verification of off-axis fiber Bragg grating bending sensor with high refractive index modulation  

作　　者：CUI Wei ZHOU Yanfang YAN Zhonghua GUO Junqi YUE Yiting CHEN Hao 

机构地区：[1]Chongqing Engineering Research Center of Intelligent Sensing Technology and Microsystem,Chongqing University of Post and Telecommunications,Chongqing 400065,China

出　　处：《Optoelectronics Letters》2022年第4期200-203,共4页光电子快报（英文版）

基　　金：supported by the Science and Technology Research Program of Chongqing Municipal Education Commission(Nos.KJQN201800626 and KJQN201800623)。

摘　　要：Off-axis FBG simulations were performed in this paper using a finite element method in conjunction with the conformal mapping technique to study the bending sensing characteristics of the off-axis FBG with high index modulation.The refractive index(RI)increase of the grating region is taken into consideration for the mode field simulation.The influences of high RI increase and the offset distance of the grating on the bending sensitivity were analyzed.Off-axis FBGs with different offset distances were fabricated using femtosecond laser with phase mask technique in standard single-mode fiber.The simulation results were verified by the experiment.A bending sensitivity of 0.055 d B/m^(-1) was achieved with an offset distance of 4μm.The simulation and experiment results suggest that the grating offset distance has a greater influence on the sensitivity of the off-axis FBG with high RI modulation than that with low RI modulation.The proposed sensor structure and simulation results can provide suggestion for the design and processing of off-axis FBG bending sensors.

关 键 词：fiber BENDING OFFSET 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]