基于双模LPFG折射率不敏感双参量传感器

环境折射率和环境温度变化是影响光纤应变测量误差的主要因素.本文利用双模光纤纤芯双模式(LP01和LP11)支持特性设计了一款环境折射率不敏感的双模光纤(DMF)长周期光纤光栅LPFG)应变传感器.设计了传感器模型结构,制作了最优化参数的传感器样品.实验测试了DMF-LPFG传感结构对外部环境中应变、温度和折射率的响应....

Refractive index insensitive two parameter sensor based on dual mode LPEG

The variation of ambient refractive index and ambient temperature is the main factor affecting the error of optical fiber strain measurement.In this paper,a strain sensor based on the dual-mode fiber(DMF)long period fiber grating(LPFG)is designed.The sensor model structure was designed,and the sensor samples with optimized parameters were produced.The experiment tested the response of the DMF-LPFG sensing structure to the strain,temperature and refractive index in the external environment.Through the Bragg grating(fiber Bragg grating,FBG)written on the single-mode fiber with a UV laser,the cross effect of the ambient temperature is solved.The results of the axial strain experiment show that the axial strain sensitivity of the new structure sensor can reach-5.4 pm/μεin the strain range of 0με~840με,which is greatly improved compared to the ordinary LPFG.The sensitivity is 58.86 pm/℃in the temperature range of 25℃~80℃,showing good linearity.At the same time,the sensor is insensitive to changes in ambient refractive index.The dual-parameter matrix is used to process the strain and temperature sensitivity of the few-mode LPFG and FBG to achieve dual-parameter simultaneous demodulation.The new composite grating structure has good sensing performance and engineering application prospects.