Faraday-Rotation Bell-Bloom Atomic Magnetometer Using An Alternating Pump-Probe Beam

We propose a scheme for a Bell-Bloom atomic magnetometer based on a single beam. In our approach, the light is periodically modulated synchronously with Larmor precession. As a result, the light that interacts with atoms is alternately polychromatic and monochromatic. When the light is polychromatic, the +/- 1st sidebands of the light are optically resonant with the atoms, and the atoms are polarized by pumping. When the light is monochromatic, a differential detection technique extracts the Faraday-rotation signal of the light, and the polarization of the light is probed. We demonstrate an experimental implementation of the Bell-Bloom magnetometer that achieves a sensitivity for magnetic-field detection of 0.25 pT/Hz(1/2) at 1 Hz. Our scheme is suitable for developing compact, miniaturized magnetometers.