基于纤芯失配和光纤布拉格光栅实现温度和应变同时测量

基于纤芯失配理论，提出了一种多模单模多模（MSM）结构与光纤布拉格光栅（FBG）级联实现温度和应变同时测量的光纤传感器。利用MSM结构的干涉谱和FBG对温度和应变的不同响应灵敏度，实现了对温度、应变的同时测量。实验结果表明，在20 ℃~80 ℃的温度范围内，MSM结构的干涉谱和FBG的温度灵敏度分别为0.091 nm/℃和0.0102 nm/℃；在0～650 με的应变范围内，应变灵敏度分别为 -0.0013 nm/με和0.0012 nm/με。因此利用敏感矩阵，即可实现对温度和应变的同时测量，且温度和应变的最大测量误差分别为±0.2 ℃和±8.25 με。该结构灵敏度高，结构简单，且不易受电磁等干扰，实验结果具有良好的线性度，在工程领域应用前景良好。

Simultaneous Measurement of Temperature and Strain Based on Core Diameter Mismatch and Fiber Bragg Grating

Based on the theory of core diameter mismatch, a kind of fiber-optic sensor composed of a multimode fiber-single mode fiber-multimode fiber (MSM) structure and a fiber Bragg grating (FBG) is proposed for simultaneous measurement of temperature and strain. Due to their different response sensitivities to temperature and strain, the temperature and strain are measured simultaneously. The experimental results show that the temperature sensitivities of the MSM structure and FBG are 0.091 nm/℃ and 0.0102 nm/℃ within the range of 20 ℃~80 ℃, respectively. The strain sensitivities are -0.0013 nm/με and 0.0012 nm/με within the range of 0~650 με, respectively. Using the sensitive matrix, simultaneous measurement of temperature and strain is realized. The maximum measurement errors of temperature and strain are ±0.2 ℃ and ±8.25 με, respectively. With high sensitivity, simple structure, immunity to electromagnetic interferences and a good linearity of the experimental results, the structure has an excellent application prospect in engineering field.