Enhanced fully optically pumped magnetic resonance with optical sideband auxiliary pumping

Abstract

We have proposed a new technique to obtain highly polarized atoms for improving the sensitivity of the all-optical Cs atomic magnetometer. In a Bell–Bloom magnetometer, the resonance pumping from the ground state F g = 3 to the excited state F e = 4 at the D1 line is used to polarize the Cs atoms and populate the sublevels of the | F g = 4 , m F = 4 ⟩ partly as the transition F g = 4 → F e = 3 remains leaking. Here we utilize a modulation technique to generate a sideband frequency to pump both transitions simultaneously, which drives more atoms to the target state | F g = 4 , m F = 4 ⟩ . This improvement significantly increases the magnetic resonance signal but with little effect on its linewidth. It is very suitable for the miniaturization of the atomic magnetometer in the future.