基于Vernier效应的光纤温度传感特性研究

Research of fiber temperature sensing characteristics based on Vernier-effect

近年来研究者借鉴游标卡尺和气压计中的游标(Vernier)结构,在多波长光纤激光传感器中使用双干涉仪级联的方式产生Vernier效应,用来提升传感器的灵敏度。本文通过仿真与实验测试,对光纤Sagnac干涉仪(FSI)和光纤法布里-佩罗干涉仪(FFPI)级联产生的Vernier效应进行了研究,设计了两种不同结构的温度传感器,研究了级联结构对传感器温度灵敏度的影响并进行了实验测试。结果表明,温度灵敏度从-1.7 nm/℃(FSI温度传感灵敏度)和0.008 nm/℃(FPI温度传感灵敏度)分别提高到10.28 nm/℃和10.64 nm/℃,基于Vernier效应,温度传感器的灵敏度提升超过6倍,实验结果与理论分析基本一致(10.82 nm/℃)。

In recent years,researchers have referred to the Vernier structure in calipers and barometers.In the multi-wavelength fiber laser sensor,the dual interferometer cascade is used to generate the Vernier effect,which is used to improve the sensitivity of the sensor.In this paper,through simulation and experimental testing,the Vernier effect generated by the cascade of fiber Sagnac interferometer(FSI)and fiber Fabry-Perot interferometer(FFPI)is studied Two kinds of temperature sensors with different structures were designed,and the effects of the cascade structure on the temperature sensitivity of the sensors were studied through experimental tests.The results show that the temperature sensitivity is increased from-1.7 nm/℃(FSI temperature sensing sensitivity)and 0.008 nm/℃(FPI temperature sensing sensitivity)to 10.28 nm/℃and 10.64 nm/℃,respectively.Based on the Vernier effect,the sensitivity of the temperature sensor is increased by more than 6 times.The experimental results are basically consistent with the theoretical analysis(10.82 nm/℃).