基于非本征光纤光栅法布里-珀罗滤波器与光电振荡器的高灵敏磁场传感  

Highly Sensitive Magnetic Field Sensing Based on Extrinsic Fiber Bragg Grating Fabry-Perot Filter and Optoelectronic Oscillator

作　　者：刘仟 高浦峰 蔡诗怡 尹彬 武蓓蕾 朱明健 陈德胜 王目光[1] Liu Qian;Gao Pufeng;Cai Shiyi;Yin bin;Wu Beilei;Zhu Mingjian;Chen Desheng;Wang Muguang(Key Laboratory of All Optical Network and Advanced Telecommunication Network,Ministry of Education,Institute of Lightwave Technology,Beijing Jiaotong University,Beijing 100044,China;Faculty of Information Science and Engineering,Ocean University of China,Qingdao 266100,Shandong,China;School of Information and Electronics,Beijing Institute of Technology,Beijing 100o81,China)

机构地区：[1]北京交通大学光波技术研究所全光网络与现代通信网教育部重点实验室,北京100044 [2]中国海洋大学信息科学与工程学院,山东青岛266100 [3]北京理工大学信息与电子学院,北京100081

出　　处：《光学学报》2024年第13期63-69,共7页Acta Optica Sinica

基　　金：国家自然科学基金(U2006217,62371035)。

摘　　要：提出并实现一种基于非本征光纤布拉格光栅法布里-珀罗(EFBG-FP)滤波器与光电振荡器(OEO)相结合的高灵敏磁场传感系统。EFBG-FP滤波器由两个端面研磨良好并插入陶瓷插芯进行轴向对准的光纤布拉格光栅(FBG)构成,然后将其与具有凹槽结构的磁致伸缩合金(MA)结合形成磁场传感单元。该EFBG-FP滤波器具有窄带滤波特性,将其放置在OEO环腔中,OEO振荡频率将由光源载频和EFBG-FP滤波器陷波中心频率的差值决定。当外界磁场变化时,EFBG-FP滤波器空气腔的长度会随MA长度的变化而变化,进而使EFBG-FP滤波器陷波波长发生漂移,最终引起OEO振荡频率发生改变。因此,可以通过监测振荡频率的变化实现对外界磁场的测量。实验结果表明,在20.2~21.8 mT磁场范围内,该系统磁场灵敏度为4.258 GHz/mT。所提出的传感系统具有高灵敏度、高分辨率、低成本和易于制作等优点,在医疗检测、地球物理、资源勘探和航空航天等领域中具有潜在的应用价值。Objective Fiber optical magnetic sensors have gained significant interest due to their small size, corrosion resistance, and ability to operate in harsh conditions. Typically, these optical fiber-based sensors are optically demodulated employing an optical spectrum analyzer(OSA) to monitor wavelength shifts or power variations, but this method suffers from slow scanning rate and poor resolution. Therefore, it is essential to suggest a magnetic sensor with a fast interrogation speed and high resolution to meet the needs of certain application fields, such as subsea weak magnetic field detection and exploration of Earth's mineral resources. Recently, optoelectronic oscillator(OEO)-based magnetic field sensing methods have been proposed with different fiber structures, such as fiber Bragg grating(FBG), Mach-Zehnder interferometer(MZI), and FBG Fabry-Perot(FBG-FP) filter. By mapping the sensing information to the frequency of the microwave signal generated from the OEO, the interrogation speed and resolution of the sensor can be strengthened. However, OEO-based magnetic field measurement using FBG and MZI exhibits low sensitivity, and the utilization of FBG-FP or phase-shifted FBG,characterized by narrow notches in their reflection spectrum, proves to be expensive and challenging in manufacturing. In this paper, we put forward an OEO-based highly sensitive magnetic field sensing scheme utilizing an extrinsic fiber Bragg grating Fabry-Perot(EFBG-FP) filter. The proposed scheme not only mitigates the complexity and cost associated with manufacturing the sensing probe but also significantly enhances the sensitivity of magnetic field sensing.Methods We use a pair of FBGs to construct an EFBG-FP filter, with both end faces being carefully milled and axially aligned by the insertion of ceramic ferrules. This is then combined with a grooved magnetostrictive alloy(MA) to create a magnetic field sensing unit. When there is a change in the external magnetic field, the length variation of the MA will effectively induce a change

关 键 词：光纤光学 光纤传感器 微波光子学 光纤布拉格光栅法布里-珀罗腔 光电振荡器 磁场测量 

分 类 号：TN29[电子电信—物理电子学]