基于幅值调制激光的Bell-Bloom测量方法  

Bell-Bloom magnetometry based on amplitude-modulated laser

作　　者：董海峰[1] 郝慧杰[1] 黄海超[1] 胡旭阳[1] 周斌权[1] 

机构地区：[1]北京航空航天大学仪器科学与光电工程学院,北京100191

出　　处：《仪器仪表学报》2014年第12期2783-2791,共9页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(61074171;61273067);北京市自然科学基金(3122025);国家重大科学研究计划(2012CB934104)项目资助

摘　　要：Bell-Bloom是一种通过检测原子进动频率测量标量磁场的方法。本文的目的是验证基于幅值调制激光的Bell-Bloom测量方法在高精度磁场测量领域的可行性,并在此基础上研究各种实验参数对共振线宽的影响。本文中采用幅值调制的方法,对抽运光的调制信号进行扫频,得到了系统的共振频谱,此时锁相放大器同时输出共振曲线和色散曲线,以用于闭环检测。通过理论仿真和实验结果的对比可以发现,线宽随着加热温度的升高、占空比的减小而单调减小,入射功率则存在最优值。另外,死区也是影响Bell-Bloom磁强计灵敏度的一个重要因素,实际应用时要尽量使被测物的主磁场垂直于抽运方向,从而避开死区,得到更为精确的磁场测量值。可参考本文的结论,对Bell-Bloom磁强计的参数进行设计和优化。Bell-Bloom is a method of measuring scalar magnetic field through detecting atomic Larmor frequency. The purpose of this paper is to validate the feasibility of the Bell-Bloom method based on amplitude-modulated laser in high sensitivity magnetic field measurement, and then study the effects of various experiment parameters on the resonance linewidth. In this paper, the amplitude-modulated method is adopted to sweep the frequency of the pumping laser modulation signal and obtain the resonant spectra of the system. At the same time, the resonance curves and disperse curves of the lock-in amplifier are outputted, which are used for close-looped detection. The comparison of theoretical simulation and experiment results shows that the linewidth monotonically decreases with the increasing of the heating temperature and the decreasing of the duty cycle, while the pumping power has an optimum value. Besides, the dead zone is another factor that influences the sensitivity of Bell-Bloom magnetometer; in practical application, the total field should be made perpendicular to the pumping laser to avoid the dead zone and obtain more accurate magnetic field measurement value. In general, the conclusion of this paper can be referred to design and optimize the parameters of Bell-Bloom magnetometers.

关 键 词：Bell-Bloom 标量磁强计 幅值调制 磁场测量 

分 类 号：TP212.13[自动化与计算机技术—检测技术与自动化装置] TH741[自动化与计算机技术—控制科学与工程]