将多模光纤两端与单模光纤正对拼接在一起,通过光纤微孔及不同芯径光纤拼接构成一个复杂的马赫-曾德尔干涉仪,利用该干涉仪构成一款新型高温与折射率传感器。实验发现,传感器透射谱中谐振峰波谷dip 1的波长只随环境温度发生线性漂移,波谷dip 1的峰值强度只随环境折射率发生线性漂移。据此利用波谷得到一个关于温度与折射率的测量矩阵,实验测得高温灵敏度达到18.55 pm/℃,折射率灵敏度达到-155.2 dB/RIU(RIU为折射率单元)。利用波谷dip 1的这个特性实现了高温与折射率同时测量,不存在交叉敏感。该传感器结构紧凑简单、性能稳定、灵敏度高。

With two ends of the multi-mode fiber and a single-mode fiber spliced together, a complex Mach-Zehnder interferometer is constructed by splicing fiber micropores with fibers of different core diameters. A new fiber optic sensor with high temperature and refractive index is constructed via the interferometer. Through experiment, it is found that the wavelength of the resonant peak valley in the transmission spectrum of the sensor linearly drifts only with the ambient temperature, while the peak intensity of the wave valley dip 1 linearly drifts only with the refractive index in the environment. A measurement matrix for temperature and refractive index of wave valley dip 1 can be obtained. The experimental results show that the high temperature sensitivity is 18.55 pm/℃ and the refractive index sensitivity is -155.2 dB/RIU (RIU is refractivity unit). Simultaneous measurement of the high temperature and refractive index is realized, and there is no cross sensitivity. The sensor has the advantages of compact and simple structure, stable performance and high sensitivity.