金属化封装光纤光栅传感器超低温特性研究

摘要

传统胶封光纤光栅(Fiber Bragg Grating,FBG)传感器的胶黏剂在超低温环境中存在着板结、与基体间热失配等问题.针对胶封光纤光栅传感器在超低温条件下进行测量的局限性,本文设计一种全金属化封装结构,并采用超声焊接的方法将光纤光栅封装固定于特种铝合金基底表面.在-160~0℃环境下,对两支FBG温度传感器的超低温传感特性进行了实验测试.结果表明,该封装形式的FBG传感器的线性度较好,相关系数均在0.99以上.它们的温度灵敏度系数在线性变化区间平均值分别为27.88pm/℃和26.17pm/℃,分别是封装前裸光纤光栅的2.75倍和2.58倍左右,提高了温度灵敏度.此金属化封装的FBG温度传感器的工艺简单,易于实现,可用于超低温恶劣环境下的温度测量.%There are usually hardening and thermal mismatch in traditional adhesive sealing FBG under the ultralow temperature environment.In order to solve the problem,a metallic packaging FBG temperature sensor was proposed,and FBG was packaged and fixed on the surface of special aluminium alloy by ultrasonic welding technique.The ultralow temperature sensing properties of two packaged FBG sensors were tested in temperature range of-160 ~ 0°C.The results indicate that the metallic-packaging FBG sensors have good linearity and the correlation coefficient of more than 0.99.The temperature sensitivity coefficients of stretching-packaging and compress-packaging FBG sensors are 27.88 pm / ℃ and 26.17 pm / °C,respectively,which are 2.75 times and 2.58 times as much as that of the bare FBG.The metallic-packaging FBG temperature sensor has excellent ultralow temperature response characteristics.