Hu Yong, Feng Y Y, Xu Chi, Xue H B, Sun Li
Appl Opt. 2014 Apr 1;53(10):2158-62. doi: 10.1364/AO.53.002158.
We have set up a coherent population trapping (CPT)-based magnetometer prototype with the D1 line of ⁸⁷Rb atoms. The dichromatic light field is derived from a fiber electro-optic modulator (FEOM) connected to an external cavity laser diode. A CPT resonance signal with a 516 Hz linewidth is observed. By feeding back the derivative of the resonance curve to the FEOM with a proportional integral controller, of which the voltage output is directly converted to the measured magnetic field intensity, the resonance peak is locked to the environmental magnetic field. The measurement data we have achieved are well matched with the data measured by a commercial fluxgate magnetometer within 2 nT, and the sensitivity is better than 8 pT/√Hz in a parallel B field.
我们利用⁸⁷Rb原子的D1线搭建了一台基于相干布居囚禁（CPT）的磁力计原型。双色光场由连接到外腔激光二极管的光纤电光调制器（FEOM）产生。观测到了线宽为516 Hz的CPT共振信号。通过使用比例积分控制器将共振曲线的导数反馈到FEOM，其电压输出直接转换为测量的磁场强度，共振峰被锁定到环境磁场。我们获得的测量数据与商用磁通门磁力计在2 nT范围内测量的数据匹配良好，并且在平行B场中灵敏度优于8 pT/√Hz。
