Analysis and Suppression of the Three-Axis Crosstalk Effect in the Modulated SERF Atomic Magnetometer

In this paper, the effects of modulation fields frequency configuration, modulation fields phase configuration and three-axis direct-current (DC) magnetic fields on the three-axis crosstalk are analyzed in the modulated spin-exchange relaxation-free (SERF) atomic magnetometer. Based on three-axis modulation fields configuration, a method is proposed to suppress the three-axis crosstalk, and the results show that the three-axis crosstalk is lower than 2%. This paper also demonstrates an in-situ magnetic compensation method, and the magnetic compensation accuracy of this method is on the order of pT. Additionally, the three-axis magnetic field closed-loop mode is showed to suppress the effect of the DC magnetic field on the three-axis crosstalk. The three-axis crosstalk is finally reduced by nearly two times compared with that of before crosstalk suppression, and the three-axis sensitivities are better than 30 fT/Hz1/2. The reduction of crosstalk is beneficial to realize the high-precision measurement of the three-axis SERF magnetometer.