Ouyang Yang, Liu Jianxia, Xu Xiaofeng, Zhao Yujia, Zhou Ai
National Engineering Laboratory for Fiber Optic Sensing Technology, Wuhan University of Technology, Wuhan 430074, China.
School of Information Engineering, Wuhan University of Technology, Wuhan 430074, China.
Sensors (Basel). 2018 Apr 11;18(4):1168. doi: 10.3390/s18041168.
A phase-shifted eccentric core fiber Bragg grating (PS-ECFBG) fabricated by electric arc discharge (EAD) is presented and demonstrated. It is composed of a fraction of eccentric core fiber fusion spliced in between two pieces of commercial single mode fibers, where a PS-FBG was written. The EAD in this work could flexibly change the amount of phase-shift by changing the discharge number or discharge duration. Because of the offset location of the eccentric core and the ultra-narrow resonant peak of the PS-ECFBG, it has a higher accuracy for measuring the directional bend. The elongation and compression of the eccentric core keep the magnitude of phase shift still unchanged during the bending process. The bending sensitivities of the PS-ECFBG at two opposite most sensitive directions are 57.4 pm/m and -51.5 pm/m, respectively. Besides, the PS-ECFBG has the potential to be a tunable narrow bandpass filter, which has a wider bi-directional adjustable range because of the bending responses. The strain and temperature sensitivities of the PS-ECFBG are experimentally measured as well, which are 0.70 pm/με and 8.85 pm/°C, respectively.
本文提出并演示了一种通过电弧放电（EAD）制备的相移偏心芯光纤布拉格光栅（PS-ECFBG）。它由一小段偏心芯光纤熔接在两根商用单模光纤之间组成，在偏心芯光纤上写入了一个相移光纤布拉格光栅（PS-FBG）。本工作中的电弧放电可以通过改变放电次数或放电持续时间灵活地改变相移量。由于偏心芯的偏移位置和PS-ECFBG的超窄谐振峰，它在测量定向弯曲时具有更高的精度。在弯曲过程中，偏心芯的伸长和压缩使相移量保持不变。PS-ECFBG在两个最敏感相反方向的弯曲灵敏度分别为57.4 pm/m和-51.5 pm/m。此外，PS-ECFBG有潜力成为一种可调谐窄带通滤波器，由于其弯曲响应，它具有更宽的双向可调范围。同时，也通过实验测量了PS-ECFBG的应变和温度灵敏度，分别为0.70 pm/με和8.85 pm/°C。
