低损耗超声波金属化光纤布拉格光栅传感特性研究  

Sensing characteristics of low-loss metallized fiber Bragg grating by ultrasonic welding

作　　者：田婧 祝连庆[1,2,3] 姚霁峰 宋言明 张钰民 TIAN Jing;ZHU Lianqing;YAO Jifeng;SONG Yanming;ZHANG Yumin(Photoelectric Information and Instruments Beijing Engineering Research Center,Beijing Information Science and Technology University,Beijing 100016,China;Key Laboratory of Modern Measurement and Control Technology Ministry of Education,Beijing 100192,China;Beijing Key Laboratory of Photoelectric Testing Technology,Beijing Information Science and Technology University,Beijing 100192,China)

机构地区：[1]北京信息科技大学光电信息与仪器北京市工程研究中心,北京100016 [2]现代测控技术教育部重点实验室,北京100192 [3]北京信息科技大学光电测试技术北京市重点实验室,北京100192

出　　处：《红外与激光工程》2024年第6期159-165,共7页Infrared and Laser Engineering

基　　金：北京市自然科学基金项目(4212048)。

摘　　要：传统胶粘式表贴封装的光纤布拉格光栅(Fiber Bragg Grating,FBG)传感器在长期使用过程中易出现蠕变、老化等现象,采用性质稳定的金属材料代替高分子聚合物胶粘剂封装可解决上述问题。采用超声波焊接法对FBG进行全覆盖式封装,实现了超低损耗表贴式金属化封装结构,并研究了其温度和应变传感特性。结果表明:采用超声波焊接法进行金属化封装对FBG造成的传输损耗仅为0.04dB,封装后FBG传感器的温度灵敏度系数为26.44pm/℃,应变灵敏度系数为1.18 pm/με,温度和应变传感拟合R-Squared均达到0.9996以上。可见,采用超声波焊接法能够实现结构简单、传感性能可靠的低损耗金属化FBG温度和应变传感器的制作。Objective Fiber Bragg grating(FBG)is widely used in the structural health monitoring of military industry,water conservancy,aerospace and other fields.FBG needs to be fixed on the object to be measured in a certain way to form heat or strain transfer.Thus,temperature or strain could be measured.Polymer adhesive is widely used in traditional FBG sensor packaging.The drawback is that polymer is prone to creep and aging during long-term use.Therefore,the deformation transfer between FBG and the measured object is mismatched,which makes the sensor ineffective.To solve this problem,metal alloy is adopted as a stable packaging material for metalizing fiber Bragg grating.Because the existing metallization method has great influence on the transmission loss caused by FBG,ultrasonic welding is studied for metallization.The temperature and strain sensing performance of the metallized sensor is verified.Methods The fiber grating was metallized by ultrasonic welding.The selected FBG is encapsulated on the beam of equal strength with tin alloy in the form of full package.The transmission and reflection spectra of FBG before and after package were observed.Temperature sensing experiments(−75-150℃)and strain sensing experiments(−560-560με)were carried out to verify the temperature and strain sensing characteristics of the metallized fiber grating sensor.Results and Discussions The shape of FBG reflection spectrum of full-wrap package is a little distorted when the package is just finished.But the degree of distortion does not affect the calculation of the central wavelength of reflection spectrum.The package transmission loss is approximately 0.04 dB(Fig.4).The full package fiber grating can realize the sensing of the entire experimental temperature experimental test range.Its temperature sensitivity is about 2.95 times that of unpackaged FBG(Fig.5).During the long,high temperature process of the temperature sensing experiment,stress release ameliorates the distortion of the reflection spectral shape of the FBG when the

关 键 词：光纤布拉格光栅 金属化封装 超声波焊接 低损耗 传感特性 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]