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。

The packaging technology of fiber Bragg gratings (FBG) has a significant impact on sensor performance. So far, two packaging methods most commonly used in the design of FBG sensors are the packaging after all grating pasting and the two-end pasting-packaging after grating pretension. As for these two packaging ways, the key parameters determining the performance of a sensor, such as sensitivity, linearity, repeatability, creep and temperature-compensation, are investigated experimentally. For each packaging way, three FBGs with the same parameters are arranged on the same equal-strength cantilever. A free and bare grating is used as a temperature reference for a contrast experiment of strain sensitivity and temperature-compensation characteristics. The experimental results show that the six FBGs under the two packaging ways have good consistency in sensitivity, linearity and repeatability, and also good creep resistance. In the test of temperature-compensation, the grating self-differential compensation effect under the same packaging way is superior to the differential compensation from the reference bare FBG. The self-differential compensation effect under the two-end pasting packaging way is the best with the wavelength shift difference less than 9 pm, better than that under the packaging way after all grating pasting (within 20 pm). In contrast, the differential compensation effect under the two-end pasting-packaging way from the reference bare grating is the worst with the maximum value up to 53 pm.