边孔光纤光栅的传感特性

报道了一种新型边孔光纤及边孔光纤光栅的研究结果。采用有限元法分析了边孔光纤内部的应力分布和双折射数值,并通过波长扫描技术对其双折射进行了测量,理论计算和实验测量结果表明双折射数值达到4×10-5。根据边孔光纤光栅两反射峰偏振态相互正交的特性,提出了一种基于偏振检测的波长检测方案对边孔光纤光栅的传感特性进行了测量。结果表明两峰中心波长间隔随温度变化的灵敏度仅有0.05 pm/℃,是普通单模光纤光栅温度灵敏度的1/184。提出了一种基于横向荷载压力增敏的新型边孔光纤光栅封装装置,使边孔光纤光栅双峰间距的压力灵敏度从5.6 pm/MPa增加到119.14 pm/MPa,增敏21倍,实现了温度不敏感的高灵敏度压力传感。

Side-Hole Fiber Grating Sensing Characteristics

The research results of a novel kind of side-hole fiber and side-hole fiber grating are reported. The finite element method is used to analyze the interior stresses distribution and the birefringence values of side-hole fiber, which is also measured by wavelength scanning method, both the theoretical and the measurement results show that the birefringence of side-hole fiber reaches 4×10-5. Utilizing the property that the polarizations of the two reflection peaks are orthogonal, the article has presented a novel scheme based on polarization detection to measure peak separation. The experimental results show that the temperature sensitivity of peak separation is 0.05 pm/℃, which is only 1/184 of the normal single-mode fiber grating. A novel transversal load sealing method is first presented in this paper, with a pressure sensitivity of 119.14 pm/MPa, which is 21 times of the pressure sensitivity of bared side-holes fiber grating 5.6 pm/MPa. The temperature-insensitive high sensitivity pressure sensing can be realized with the side-hole fiber grating.