一种高灵敏度复合环形腔结构的光纤激光拍频位移传感方案  

High sensitivity fiber displacement sensor based compound ring laser cavity with linear variation of beat frequency signal

作　　者：田晶 侯美江 江阳 张红旭 白光富 冯豪 Tian Jing;Hou Mei-Jiang;Jiang Yang;Zhang Hong-Xu;Bai Guang-Fu;Feng Hao(College of Physics,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学物理学院,贵阳550025

出　　处：《物理学报》2020年第18期206-211,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61801134,61835003,61965004);贵州省科技计划(批准号:黔科基础[2019]1127);贵州大学“SRT计划”(批准号:贵大SRT字(20)号)资助的课题.

摘　　要：提出并验证了一种高灵敏度复合环形腔结构的激光拍频位移传感技术方案.该方案采用环形腔复合直腔的谐振腔结构,利用激光拍频传感原理实现传感系统信号的解调.该结构通过掺饵光纤放大器提供增益,采用光纤布拉格光栅作为传感头兼直腔反射镜,利用π相移光栅进行窄带滤波.理论分析结果表明激光拍频频率随传感头应变的增加线性减小;实验结果显示,当监测频率为1.7483 GHz时,传感器的灵敏度达到了86.19 kHz/mm,线性拟合度为0.9973,最小可分辨位移为10μm左右,该系统同时具有空间位置分辨的潜力.结果表明所提出的新型位移传感方案是可行的,结构紧凑、简单实用、灵敏度高,为将来实现高精度、微型化以及分布式传感系统打下基础.A novel fiber sensor based compound ring laser cavity with linear variation of frequency is proposed and demonstrated experimentally.The compound ring laser cavity is comprised of a ring cavity and a straight cavity.This system can generate the beat frequency spectrum by employing an erbium doped fiber amplifier,a fiber Bragg grating is used as a sensor head and the straight cavity reflector,aπphase shifted fiber Bragg grating serves as a microwave photonic passband filter.The principle of the proposed sensor is theoretically analyzed,showing that as the displacement increases the beat frequency decreases,and there exists a linear relationship between displacement change and beat frequency shift.In experiment,it is shown that the sensor has a high sensitivity of about 86.19 kHz/mm and can achieve a good linear response(R^2=0.9973),and that the minimum monitored displacement is about 10μm.The measurement results demonstrate that the sensor is accurate,sensitive,and the proposed sensor system has a compact and simple structure,which makes it convenient for more applications in future.

关 键 词：光纤激光传感 复合环形腔 拍频 掺饵光纤放大器 

分 类 号：TN253[电子电信—物理电子学] TP212[自动化与计算机技术—检测技术与自动化装置]