摘要
针对氦激光泵浦磁力仪在磁场测量中存在工作盲区的难题,提出了一种基于旋转偏振的无盲区磁场探测方法。采用线偏振光激发氦原子的张量磁矩,根据检测光的归一化光谱求解直流、一倍频和二倍频信号的解析解。首先分析各检测信号的角相关特性,结合一倍频色散分量的过零点和二倍频吸收分量的幅度判据调整光偏振方向,使偏振方向始终与外磁场保持垂直,利用正交亥姆霍兹线圈产生旋转射频电磁场,并且始终与光偏振方向平行。最后利用二倍频色散分量的过零点锁定磁场模值。实验测试结果表明,所提方法能够实现无盲区磁场探测,磁场检测灵敏度为0.4 pT/√Hz@1 Hz。
Aiming at the difficult problem that there exists operation dead zone in magnetic field measurement using helium laser-pumped magnetometer, a dead-zone free magnetic field detection method based on rotating polarization is proposed. A linearly-polarized light is used to excite the magnetic tensor moment of the helium atoms, and the analytic solutions of the DC, fundamental frequency and second harmonic frequency signals are derived based on the normalized spectrum of the detected light. The angular correlation characteristics of different detection signals are firstly analyzed, then the zero-crossing point of the dispersion component of the fundamental frequency signal and the amplitude criterion of the absorption component of the second harmonic frequency signal are combined to adjust the polarization direction, so as to achieve a consistent vertical relationship between the polarization direction and the magnetic field. The orthogonal Helmholtz coils are used to generate a rotating ratio-frequency electromagnetic field whose direction is always parallel to the polarization direction. Finally, the zero-crossing point of the dispersion component of the second harmonic frequency signal is utilized to lock the magnetic field. The experiment test results show that the method proposed in this paper could achieve dead-zone free detection for the magnetic field with a magnetic field detection sensitivity of 0.4 pT/√Hz@1 Hz.
作者
时洪宇
宋晓林
刘金胜
史钰峰
Shi Hongyu;Song Xiaolin;Liu Jinsheng;Shi Yufeng(Shangdong Institute of Space Electronic Technology,China Academy of Space Technology,China Aerospace Science&Technology Corporation,Yantai 264670,China;Engineering Laboratory for Quantum Magnetism&Electromagnetism of Shandong Province,Yantai 264670,China)
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2020年第7期54-62,共9页
Chinese Journal of Scientific Instrument
基金
装备预研共用技术和领域基金(61400030301)
山东半岛国家自主创新示范区发展建设资金(ZCQ18111)项目资助
关键词
氦激光泵浦磁力仪
角相关特性
无盲区
旋转偏振
helium laser-pumped magnetometer
angular characteristic
dead-zone free
rotating polarization
