飞秒激光直写多芯FBG及耦合波导的二维矢量位移传感研究  

Two-Dimensional Vector Displacement Sensing Based on Femtosecond Laser Direct-Writing Multicore Fiber Bragg Grating and Coupled Waveguides

作　　者：樊宇 包维佳 廖常锐[1,2,3] 王义平[1,2,3,4] Fan Yu;Bao Weijia;Liao Changrui;Wang Yiping(State Key Laboratory of Radio Frequency Heterogeneous Integration,Shenzhen University,Shenzhen 518060,Guangdong,China;Guangdong and Hong Kong Joint Research Centre for Optical Fiber Sensors,Shenzhen University,Shenzhen 518060,Guangdong,China;Shenzhen Key Laboratory of Ultrafast Laser Micro/Nano Manufacturing,Shenzhen University,Shenzhen 518060,Guangdong,China;Guangdong Laboratory of Artificial Intelligence and Digital Economy(Shenzhen),Shenzhen 518107,Guangdong,China)

机构地区：[1]深圳大学射频异质异构集成全国重点实验室,广东深圳518060 [2]深圳大学广东省光纤传感技术粤港联合研究中心,广东深圳518060 [3]深圳大学深圳市超快激光微纳制造重点实验室,广东深圳518060 [4]人工智能与数字经济广东省实验室(深圳),广东深圳518107

出　　处：《中国激光》2025年第1期119-127,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(62122057,62075136);广东省基础与应用基础研究基金(2022B1515120061);深圳市科技计划(ZDSYS20220606100405013);中核集团领创基金。

摘　　要：提出了一种利用单通道测量多路信号的多芯光纤布拉格光栅(FBG)二维矢量位移传感结构,该传感结构的主体基于飞秒激光直写技术制备。通过在多芯光纤的中间芯和侧芯中分别刻写FBG,并进一步制备能够连接中间芯与侧芯的直耦合波导,可以实现单个纤芯复用多路传感光信号的功能,因此能够避免扇入扇出器件的使用。基于该传感结构,进行了方向角为0°~360°的二维矢量位移传感测试,对方向角的测试结果进行了计算重构,并比较了实际施加角度与计算重构角度之间的误差。另外,测试了传感器在不同位移量下的方向响应,结果表明传感器的方向响应始终呈近似正弦分布。最后,测试了传感器在不同方向角下的位移响应,得到最大位移灵敏度为0.28 nm/mm。Objective In recent years,multicore fiber Bragg grating(FBG)vector displacement sensors have become a research hotspot in the field of vector displacement sensing because of their multidimensional measurement capability,high sensitivity,high resolution,and high precision.However,in practical applications,multicore FBG vector displacement sensors require a fan-in and fan-out device to realize multichannel signal demodulation.The use of this device not only increases the difficulty of fiber fusion splicing and reduces the compactibility of the sensor but also increases the cost and complexity of the system and reduces modulation efficiency,which poses a challenge to the practical application of the existing multicore FBG vector displacement sensor.In this study,a vector displacement sensing structure based on multicore FBGs and coupled waveguides is proposed,to measure multiple signals in a single channel and avoid the use of fan-in and fan-out device.Methods First,for preparation,a sensing structure was studied.FBGs were inscribed in the central core(core 1)and two outer cores(core 2 and core 3)with an azimuth difference of 60°for a seven-core fiber,using femtosecond laser direct-writing technology.In addition,straight coupled waveguides for connecting core 1 to core 3 and core 1 to core 2 were prepared,to enable signal light transmission back and forth between the central and outer cores.Figure 2 shows the principle of multiplexing multichannel sensing signals,using a single core based on this structure.Subsequently,the principle of displacement sensing based on multicore FBGs was theoretically analyzed.Finally,based on the self-built displacement testing system(Fig.7),a displacement-sensing test was performed on the prepared sensing structure,to verify its performance.Results and Discussions Femtosecond laser direct writing technology was used to prepare a reference FBG(FBG1)for auxiliary positioning and temperature compensation in core 1,and a sensing FBG(FBG2 and FBG3)for detecting displacement changes in cor

关 键 词：矢量位移传感 飞秒激光直写 多芯光纤 光纤布拉格光栅 波导 

分 类 号：TN249[电子电信—物理电子学]