光纤光栅的粘贴封装工艺对传感器的性能有重要影响。目前光纤光栅传感器设计中最常用的两种封装方式分别是将光栅全部粘贴后进行封装以及将光栅预拉伸后对光栅两端进行粘贴封装。在这两种封装方式下,对光纤光栅的测量灵敏度、线性、重复性、蠕变、温度补偿等决定传感器核心性能的参数开展了实验研究。每种封装方式下,均将3支参数相同的光纤光栅布置在同一等强度梁上,并布置1支自由状态的裸光栅作为温度参考,开展应变感测特性和温度补偿特性方面的对比实验。实验结果表明,两种封装方式下的6支光纤光栅在灵敏度、线性、重复性方面均具备良好的一致性及抗蠕变能力;温度补偿测试中,同种封装方式的光栅自差分补偿的效果明显优于参考裸栅的差分补偿结果;光栅两点粘贴封装方式的自差分补偿效果最好,达到9 pm以内,优于光栅全部粘贴封装的结果(小于20 pm);光栅两端粘贴封装与参考裸栅差分补偿的效果最差,最大达53 pm。

During last decades, sensor elements based on the fiber Bragg grating (FBG) have been widely studied and developed due to the advantages of immunity to electromagnetic interference, compact size, high precision, and so on. The FBG itself is sensitive to axial strain and temperature variation directly and can indirectly measure these complex physical parameters, such as pressure, displacement, and vibration, by using some specially designed elastic structures to convert them into the axial strain of the FBG. Whether the FBG is fixed on the measured object to measure the strain directly or fixed on an elastic structure body to measure other physical quantities, these types of FBGs could be collectively called as strain sensing FBGs. The packaging of the FBG has important influence on FBG characteristics that directly affect the measurement accuracy, such as strain transfer, temperature characteristic, and spectral shape. This paper summarizes the packaging methods and corresponding temperature compensation methods of the currently reported strain sensing FBGs, focusing especially on fully pasted FBG, pre-stretched FBG with double-end fixed, and metallic packaging. Furthermore, the advantages and drawbacks of different packaging methods have been analyzed, which can provide a reference for future researches.