单光束小型SERF原子磁力计光频移抑制研究  

Suppression of Optical Frequency Shift Based on Single⁃Beam Compact SERF Atomic Magnetometer

作　　者：缪柯萱 胡涛 郭清乾 冯晓宇 张寅 常严[1,2,3] 杨晓冬 Miao Kexuan;Hu Tao;Guo Qingqian;Feng Xiaoyu;Zhang Yin;Chang Yan;Yang Xiaodong(School of Biomedical Engineering(Suzhou),Division of Life Sciences and Medicine,University of Science and Technology of China,Hefei 230026,Anhui,China;Medical Imaging Department,Suzhou Institute of Biomedical Engineering and Technology,Chinese Academy of Sciences,Suzhou 215163,Jiangsu,China;Jihua Laboratory,Foshan 528200,Guangdong,China;Jinan Guoke Medical Technology Development Co.,Ltd.,Jinan 250102,Shandong,China)

机构地区：[1]中国科学技术大学生命科学与医学部生物医学工程学院(苏州),安徽合肥230026 [2]中国科学院苏州生物医学工程技术研究所医学影像技术研究室,江苏苏州215163 [3]季华实验室,广东佛山528200 [4]济南国科医工科技发展有限公司,山东济南250102

出　　处：《中国激光》2024年第15期194-202,共9页Chinese Journal of Lasers

基　　金：苏州市基础研究试点项目(SJC2021024);山东省自然科学基金青年项目(ZR2022QF098);季华实验室项目(X190131TD190)。

摘　　要：随着量子操控与光电检测技术的进步,原子磁力计作为新型量子极弱磁传感器得到了快速发展。工作在无自旋交换弛豫(SERF)状态下的原子磁力计相较于传统极弱磁探测传感器,具有无需制冷、结构紧凑、运维成本低及灵敏度高等优势,被广泛应用于诸多领域。而圆偏振抽运光频率失谐产生的光频移现象会对SERF原子磁力计的测量正交性及输出响应产生重要影响。基于自研小型单光束SERF87Rb原子磁力计,提出了一种基于非敏感轴响应分析的光频移抑制方法,精准绘制了光频移曲线,并结合光吸收曲线,分析和确定了SERF原子磁力计的中心共振频率。此外,分析发现,利用该方法对光频移进行抑制可显著降低磁力计测量轴间的耦合串扰,提升测量正交性和敏感轴输出响应,实验结果证明了该抑制方法的有效性。基于上述研究结果,进一步对比发现,抑制光频移可提升自研小型SERF原子磁力计的性能,最终灵敏度在140 Hz的带宽范围内可达13 fT·Hz-1/2,动态范围约为±3 nT。Objective With advancements in quantum manipulation and optoelectronic detection technologies,the atomic magnetometer,a novel quantum extremely-weak magnetic sensor,has experienced rapid development.Operating in the spin exchange relaxation free(SERF)state,atomic magnetometers offer numerous advantages,including non-cryogenic operation,compact structure,low maintenance costs,and high sensitivity,making them widely applicable in various fields.However,the phenomenon of optical frequency shift,induced by off-resonant circularly polarized pumping light,critically affects the orthogonality of measurement and output response in SERF atomic magnetometers.This study proposes a method for suppressing optical frequency shift based on the analysis of the non-sensitive axis response using a self-made compact single-beam SERF 87 Rb atomic magnetometer.The curve of optical frequency shift,combined with the curve of light absorption,is precisely plotted and analyzed to determine the central resonant frequency of the SERF atomic magnetometer.The analysis indicates that employing this suppression method significantly reduces coupling crosstalk between the measurement axes of the magnetometer,thereby enhancing the orthogonality and output response of the sensitive axis.Experimental results validate the effectiveness of this suppression method.Further comparison reveals that the performance of the self-made compact SERF atomic magnetometer is enhanced by suppressing optical frequency shift,resulting in a sensitivity of 13 fT/√Hz within a bandwidth of 140 Hz and a dynamic range of approximately±3 nT.Methods The optical frequency shift direction is regarded as the photon spin direction,which is equivalent to the existence of an equivalent virtual magnetic field in the direction of the pumping light(x-axis).Due to this fictitious magnetic field,the sensitive axis(z-axis)of the SERF atomic magnetometer reacts to signals from the non-sensitive axis(y-axis).Applying a weak oscillating magnetic field at 40 Hz to the y-axis and a direc

关 键 词：医用光学 原子磁力计 无自旋交换弛豫 光频移 虚拟磁场 正交性 

分 类 号：O439[机械工程—光学工程]