A laser pump-re-pump atomic magnetometer

J. P. Carrico, T. S. Stein

Ailin Yang, Guoqing Yang, Xunming Cai +2 more

We demonstrate experimentally an atomic magnetometer based on optical pumping theory, a magnetic resonance that is induced by a radio frequency field and dependent on the magnetic field strength. Compared with the conventional method using one radiation field, which is used not only as the probe beam but also as a pump beam, the additional re-pump beam can increase remarkably the amplitude of the signal. It is shown that the amplitude of the magnetic field resonance signal can increase more than 55% by using an additional re-pump beam, which makes the sensitivity of the magnetometer higher. Finally, we investigate the relation between amplitude of the signal and re-pump laser power, and calculate the atomic population in the trapping states with rate equations.

Peter D. D. Schwindt, John E. Kitching, Svenja A. Knappe +4 more

Yang Li, Xue-Jing Liu, Hongwei Cai +2 more

Abstract The alkali-metal density ratio is one of the primary design parameters in hybrid optical pumping magnetometers. Here, experiments were conducted with a hybrid optically-pumped atomic magnetometer using a cell containing potassium and rubidium. Potassium atoms are pumped by a laser and become polarized. Rubidium atoms are polarized via collisions with potassium atoms and can be probed. The light shift was eliminated by adjusting the density ratio of potassium to rubidium atoms and by optimizing the pump laser parameters. The effect of fluctuations in the laser power and frequency were minimized as a result. The optimal density ratio and magnetic field sensitivity were 1:277 and 0.68 fT Hz −1/2 , respectively.

Xian Jin Zeng, Jun Hai Zhang, Qiang Liu +2 more

Recently, atomic magnetometers have been researched widely for its ultra high sensitivity. But the influence of pump light’s duty cycle on atomic magnetometers has been concerned little. In this paper, we described a sensitive cesium atomic magnetometer based on circular dichroism, which had the advantage of easily locking the probing laser to the necessary frequency. We experimentally investigated the amplitudes and linewidths of magnetic resonance signals at different modulated duty cycle of the pump light. The result indicated that our magnetometer achieved the highest sensitivity at the duty cycle of 30%. It’s valuable for optimizing the sensitivity of most atomic magnetometers.

Svenja A. Knappe