Characterization Of Temperature And Curvature Dual-parameter Sensors Based On Asymmetric Dual-core Fiber

Monitoring and control of temperature and curvature are particularly important in extreme environments such as high temperature and pressure,high electromagnetic field radiation,and strong acids and bases,while changes in refractive index in special environments can cause a certain degree of interference with the detection of temperature and curvature.Fiber optic sensors have the advantages of high interference immunity and small size compared with traditional electrical sensors.Asymmetric dual-core fiber(ADCF)is easy to be prepared as a new type of fiber microstructure sensor based on its special fiber structure.Therefore,it is of great importance to investigate the temperature and curvature sensors of refractive index insensitive bias dual-core fiber.In this paper,the current status of domestic and international research based on temperature sensors and curvature sensors is investigated,and three types of refractive index insensitive biased dual-core optical fiber sensors are prepared on the basis of existing research,and their sensing characteristics are analyzed in detail,including:Firstly,based on the coupling mode theory,the transmission characteristics of dual-core fiber are analyzed,the transmission mode of ADCF is studied and the dual parametric sensing and demodulation theory is analyzed;Secondly,a dual parametric sensor based on multimode fiber(MMF)cascaded ADCF was prepared and studied,the effects of MMF length and ADCF length on the transmission spectrum were analyzed,the refractive index,temperature and curvature sensing principles of MMF cascaded ADCF sensor based on MMF were analyzed theoretically,the refractive index,temperature and curvature sensing characteristics of the sensor were investigated by focusing on simulation and experiment,and a dual wavelength sensitivity matrix was established to realize the simultaneous measurement of temperature and curvature;Then,the sensor based on MMF cascade ADCF bias core rotary fusion was prepared,the refractive index,temperature and curvature sensing principles of the sensor were analyzed,the refractive index,temperature and curvature experimental platform was built,the transmission characteristics of the sensor were explored by focusing on simulation and experiment,and the simultaneous measurement of both temperature and curvature parameters was realized;Finally,the MMF cascade peanut ADCF-based sensor was prepared and explored,the effect of the coarse cone diameter on the transmission spectrum was analyzed,the sensing characteristics of refractive index,temperature and curvature of the sensor were simulated and focused on refractive index,temperature and curvature sensing experiments,and the simultaneous measurement of temperature and curvature was achieved by establishing dual-wavelength sensitivity moments.