LI Yongqian,FAN Haijun,WANG Lei,ZHANG Lixin,LIU Ting.Bend-tolerant fiber sensor based on BOTDR system[J].Optoelectronics Letters,2022,(6):343-348 Bend-tolerant fiber sensor based on BOTDR system Author Name Affiliation LI Yongqian  Department of Electronic and Communication Engineering, North China Electric Power University, Baoding 071003, China Hebei Key Laboratory of Power Internet of Things Technology, North China Electric Power University, Baoding 071003, China Baoding Key Laboratory of Optical Fiber Sensing and Optical Communication Technology, North China Electric Power University, Baoding 071003, China  FAN Haijun  Department of Electronic and Communication Engineering, North China Electric Power University, Baoding 071003, China Hebei Key Laboratory of Power Internet of Things Technology, North China Electric Power University, Baoding 071003, China Baoding Key Laboratory of Optical Fiber Sensing and Optical Communication Technology, North China Electric Power University, Baoding 071003, China  WANG Lei  Department of Electronic and Communication Engineering, North China Electric Power University, Baoding 071003, China Hebei Key Laboratory of Power Internet of Things Technology, North China Electric Power University, Baoding 071003, China Baoding Key Laboratory of Optical Fiber Sensing and Optical Communication Technology, North China Electric Power University, Baoding 071003, China  ZHANG Lixin  Department of Electronic and Communication Engineering, North China Electric Power University, Baoding 071003, China Hebei Key Laboratory of Power Internet of Things Technology, North China Electric Power University, Baoding 071003, China Baoding Key Laboratory of Optical Fiber Sensing and Optical Communication Technology, North China Electric Power University, Baoding 071003, China  LIU Ting  Department of Electronic and Communication Engineering, North China Electric Power University, Baoding 071003, China Hebei Key Laboratory of Power Internet of Things Technology, North China Electric Power University, Baoding 071003, China Baoding Key Laboratory of Optical Fiber Sensing and Optical Communication Technology, North China Electric Power University, Baoding 071003, China  Abstract:       A simple and inexpensive sensing structure, single mode fiber (SMF) alignment fusion to 62.5 μm stepped index-multimode fiber (SI-MMF), combined with Brillouin optical time domain reflectometry (BOTDR) system, is used as a distributed sensor in the field of structural safety and health monitoring (SSHM) of large infrastructures in terms of its prominent bending resistance. The bend loss principle and influencing factors of the fiber are analyzed, and the bending resistances of different fibers are discussed on the basis of theoretical and experimental comparisons. The bend-tolerant capacity and temperature sensing characteristics of the 5 km sensing structure are measured by using the self-developed frequency-shifted local heterodyne BOTDR system. The results show that the proposed sensing structure has excellent bend-tolerant capacity with a minimum bend radius and temperature measurement error of 1.25 mm and 0.69 °C, respectively, which indicates that the proposed sensing structure has huge potential in the field of SSHM of large infrastructures. Hits: 318 Download times: 1 View Full Text    Download reader