高灵敏度弱磁传感器研究

磁传感器在生物医学、资源探测和航空航天等领域有巨大的应用价值,基于原子自旋的弱磁传感器拥有目前最高的磁场测量灵敏度。但通常的方案采用射频场调制或远离共振的激光检测,前者增加了磁力仪的线宽,而后者对激光频率的锁定带来了困难。为了解决以上问题,提出了一种基于激光强度调制和圆二向色性检测的原子弱磁传感器方案,详细描述了其工作原理和系统构成,并对原子弱磁传感器的性能进行了测试。实验结果表明:原子弱磁传感器的磁共振线宽为22 Hz,在对恒定磁场进行30 min连续测量时,峰峰值抖动小于9 pT,灵敏度达到了0.12 pT/Hz1/2。

Research of high sensitivity weak magnetic sensor

Magnetic sensors has great application value in biomedical, resource exploration, aeronautics and astronautics. Weak magnetic sensors based on atomic spin effect has been the most sensitive instruments in magnetic field measurement. These sensors usually employ the sheme of RF modulation or off-resonant laser light detection. The former will give rise to magnetometer linewidth broadening and the latter will make it difficult to lock laser freqency. In order to solve above problem, a project based on laser intensity modulation and circular dichroism detection is proposed. The operation principle and system configuration are described in detail, and the properties of atomic weak magnetic sensor is tested. Experimental results show that the magnetic resonant linewidth is 22 Hz, with 30 min continuous measurement of constant magnetic field, its peak to peak value is less than 9 pT and sensitivity achieves 0.12 pT/Hz^1/2.