Optimized gas pressure of an Rb vapor cell in a single-beam SERF magnetometer

We present a theoretical and experimental study of a single-beam spin-exchange relaxation-free magnetometer in Rb-87 vapor cells under different nitrogen gas pressures. The spin relaxation rate is a key component to limit the magnetic sensitivity, and the zero-field resonance method was used to measure the spin relaxation rates of different alkali metal cells. Simultaneously, in a single-beam spin-exchange-relaxation-free (SERF) magnetometer, we demonstrated that the fundamental magnetic field sensitivity was also limited by the pumping light intensity. Based on our theoretical analysis and experimental results, we determined the optimal pumping light intensity and optimal gas pressure. We experimentally demonstrated that the magnetic field sensitivity was 8.89 fT/root Hz in the single-beam configuration, with an active measurement volume of 3 x 3 x 3 similar to mm(3). (c) 2021 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

In this study, a theoretical and experimental investigation on a single-beam spin-exchange relaxation-free magnetometer in Rb-87 vapor cells under different nitrogen gas pressures was conducted. The spin relaxation rate and the pumping light intensity were found to limit the magnetic sensitivity. The optimal pumping light intensity and gas pressure were determined based on theoretical analysis and experimental results. The experimental demonstration achieved a magnetic field sensitivity of 8.89 fT/root Hz in the single-beam configuration.