Zero-field calibration for single-beam atomic magnetometer

Di Zhan, Yaoguo Wang, Ziao Liu +3 more

Khanuengchat Saenyot, Yuya Shoji, Shunya Takahashi +1 more

In this letter, we propose a simple and rapid method for zero field calibration of single elliptically polarized beam atomic magnetometers. This method uses a wobble adjustment that applies a small amplitude and low-frequency (70 Hz) ac magnetic field and sweeps the dc magnetic field. The second harmonic signal reaches its maximum when the dc magnetic field noise is zero. Our single-beam atomic magnetometer operates with elliptically polarized light, which has both circularly and linearly polarized light components. The wavelength of a single beam for a rubidium atom was determined to be 780.206 nm with a power of 2.72 mW.

J. P. Carrico, T. S. Stein

Wei Xiao, He Wang, Xiangzhi Zhang +5 more

In this article, we propose an in situ method to calibrate the magnetic-field coil systems in optically-pumped magnetometers. The method is based on parametric resonance induced by nonresonant radio-frequency (RF) fields, and is especially suitable for microfabricated single-beam zero-field atomic magnetometers. We have experimentally and theoretically demonstrated this method with a single-beam spin-exchange-relaxation-free (SERF) magnetometer, and the experiment results are in line with theoretical expectations.

Yuya Shoji, Khanuengchat Saenyot, Shunya Takahashi +1 more

A single-beam atomic magnetometer with elliptical polarization is simple in construction because it requires only one laser for both pumping and probing. When a small-signal magnetic field is input into the magnetometer after the DC magnetic field is set to zero, a full-wave cleared waveform is output. This characteristic is appropriate for calibration and measurement of DC magnetic fields, because the bias of such fields affects their sensitivity. In this paper, we examined the step-response waveform when a pulsed magnetic field with various DC magnetic-field biases was applied. The response waveform was measured in the time domain with an oscilloscope. The oscillation frequency did not depend on the step-magnetic-field difference but on the amplitude when changing from an absolute-zero magnetic field to a finite magnetic field. Because the DC magnetic field can be determined by measuring the frequency, the bias magnetic field of the atomic magnetometer can be adjusted to maintain the optimal point of operation.

Shushan Gao, Xiaoyu Li, Jianwei Sheng +5 more