纯石英芯光纤光栅高温应变响应特性

Response Characteristics of Pure-Quartz-Core Fiber Bragg Grating Under High Temperature Strain

针对高温条件下应变测量受限问题,对飞秒脉冲激光刻写的Ⅱ型纯石英芯光纤光栅(FBG)的温度及应变特性进行了研究。实验结果表明,纯石英芯FBG在20~1000℃温度范围内表现出良好的线性度,相关系数为0.9996,温度灵敏度为14.07pm/℃;纯石英芯FBG在400℃及以下的高温环境中加载均匀应变时表现出良好的波长稳定性,温度超过500℃时的应变加载导致光纤伸长,引起中心波长的红移。

In order to solve problem of the strain measurement limitation under high temperature, the temperature and strain characteristics of the type II pure-quartz-core fiber Bragg grating （FBG） written by femtosecond pulse laser are studied. Experimental results show that when the temperature is ranging from 20 ℃ to ]000 ℃, the pure- quartz-core FBG exhibits good linearity with the correlation coefficient of 0. 9996 and the temperature sensitivity of 14.07 pm/℃. When the temperature is under 400 ℃, the pure-quartz-core FBG exhibits good wavelength stability under the uniform strain. When the temperature is above 500 ℃, the strain loading leads to fiber elongation and the red shift of the center wavelength.