基于SMS结构的多功能光纤传感器

Multifunctional fiber sensor based on SMS structure

基于干涉仪型光纤传感器的基本原理,利用大芯径多模光纤与单模光纤的耦合特性,设计了一款"单模光纤-多模光纤-单模光纤"结构的光纤传感器。由于光纤芯径不匹配,形成Mach-Zehnder干涉仪。干涉仪的透射谱具有许多稳定的谐振峰,自由空间光谱间隔大。这些谐振峰的中心波长对环境温度与轴向应变较敏感,因此可以通过考察谐振峰的中心波长随环境温度与轴向应变的变化关系进行温度与应变测量。利用波长调制法,获得最大温度灵敏度为12.00 pm/℃,最大应变灵敏度为-1.709 pm/με。由于温度与应变变化引起谐振峰的中心波长向不同方向漂移,通过监测两个谐振峰的中心波长同时随环境温度与轴向应变的变化关系,构建测量矩阵实现多参量同时测量。传感器具有结构简单、制作容易、重复性好、成本低、灵敏度较高等优点,具有一定的应用前景。

Based on the basic principle of interferometer fiber sensor,a fiber sensor with singlemode fiber-multimode fiber-singlemode fiber is designed by using of coupling characteristics of large core diameter multimode fiber and single mode fiber.Because the fiber core diameter does not match,the Mach-Zehnder interferometer is formed.The transmission spectrum of the interferometer has many stable resonance peaks,and the free space spectrum range is large.The central wavelength of these resonant peaks is sensitive to ambient temperature and axial strain,so the temperature and strain measurement can be carried out by examining the relationship between the central wavelength of these resonant peaks and the ambient temperature and axial strain.The maximum temperature sensitivity is 12.00 pm/℃and the maximum strain sensitivity is-1.709 pm/μεby wavelength modulation.As the temperature and strain change cause the center wavelength of the resonance peak to drift in different directions.By monitoring the relationship between the central wavelength of the two resonance peaks and ambient temperature and axial strain,the measurement matrix is constructed to realize multi-parameter simultaneous measurement.The sensor has the advantages of simple structure,easy fabrication,good repeatability,low cost and high sensitivity,and has a certain application prospect.