Research On The Temperature And Curvature Characteristics Of The Dumbbell-shaped Sensor Based On The Core-offset Heterogeneous Fiber

With the acceleration of modernization,the interaction of information is becoming more and more frequent.Optical fiber sensors have opened up new opportunities in the Internet of Things era due to their advantages of corrosion resistance and electromagnetic interference resistance.At present,the detection of ambient temperature and bending of structures has received widespread attention.Microstructured fiber optic sensors can realize vector curvature detection while realizing temperature detection.Based on the research status of microstructured fiber optic sensors at home and abroad,this paper focuses on temperature and vector curvature detection.Three kinds of dumbbellshaped optical fiber sensors with different structures are fabricated by using Eccentric Heterogeneous Fiber(EHF),and their transmission characteristics and sensing properties are investigated.The main contents are as follows.Firstly,according to the basic principle of dual-mode interference,the influence of temperature and curvature on the transmission spectrum and the demodulation method is analyzed,and the demodulation methods of dual-parameter detection are explored.Secondly,a dumbbell-shaped Eccentric Heterogeneous Fiber(EHF)sensor is designed and fabricated.The influence of the length of EHF and the diameter of the thick cone on the transmission spectrum is investigated.The temperature and curvature detection device platform are built,and the temperature sensing experiment is carried out.The characteristics of sensor vector curvature are mainly explored.The transmission spectrum and sensitivity of the sensor are obtained by theoretical simulation.The detection of temperature and curvature is realized by double parameter demodulation matrix.Then,based on the dumbbell-shaped EHF sensor,a clad-corroded dumbbell-shaped EHF sensor was prepared by etching the EHF part.The bending simulation model is established,and the sensing characteristics of temperature and curvature of the sensor are simulated to realize the simultaneous detection of temperature and curvature.Finally,a PDMS-coated dumbbell-shaped EHF sensor was investigated and fabricated.The transmission mechanism was further analyzed and temperature and curvature sensing experiments were carried out.The transmission spectrum and sensitivity of the sensor are simulated to realize the detection of two parameters.