中文摘要：

研制了一种新颖的菱形光纤布拉格光栅（FBG）低温传感器。采用有限元方法分析了这种结构的力学性能和温度特性。将该装置置于低温（液氮）拉伸设备中，实验研究了这种封装形式的低温应变特性。采用光纤布拉格光栅网络分析仪和低温应变仪，分别测量了液氮温度下菱形应变传感器的波长变化量和应变变化值，测得其应变系数为-0．7185μe／pm，线性度达到0．9998。

英文摘要：

A new design of Fiber Bragg Grating（FBG）strain sensor with rhombic encapsulation structure was developed. The mechanical properties and temperature characteristics of the FBG strain sensor were analyzed by using the limited element method. The wavelength and strain change of the FBG sensor were measured under liquid nitrogen temperature. The results indicate that the strain coefficient of the FBG strain sensor is -0. 718 5 μg/pm,with excellent linearity up to 0. 999 8.