基于单模光纤偏芯结构的光纤折射率传感器研究

基于迈克尔逊(Michelson)干涉仪(MI)原理,结合光纤传感器的特性,设计和实现了一种单模光纤(SMF)偏芯干涉仪结构光纤折射率传感器,并针对蔗糖溶液进行了折射率的测量。实验结果表明:这种传感器的传感范围在1.33～1.39时,特征波长与外界折射率有单调的递减变化关系,蔗糖折射率每变化0.01时,特征波长平均变化约为0.12nm。这种传感器结构简单,灵敏度较高,能够实现液体折射率与浓度变化的在线检测。

Investigation of fiber optic refractive index sensor based on single-mode fiber core-offset attenuartor

Based on the principle of Michelson interferometer and the characteristics of fiber optic sensors,this paper has developed a novel single-mode core-offset fiber optic interferometer sensor,and uses it for the refractive index measurement in sugar solution.Experimental results show that when the sensing range is from 1.33 to 1.39,there will be a better progressive decrease relationship between the characteristic wavelength and the refractive index;the refractive index change of 0.01 of the sucrose will lead to an approximate average variation of 0.12 nm in the characteristic wavelength.This sensor can be used for on-line liquid refractive index and concentration monitoring with simple structure and high sensitivity.