Dead-zone-free atomic magnetometer based on hybrid Poincaré beams

Abstract

In this paper, we present the experiment and the theory scheme of light-atom interaction in atomic magnetometers by using a hybrid Poincaré beam (HPB) to solve an annoying problem, named “dead zone.” This kind of magnetometer can be sensitive to arbitrary directions of external magnetic fields. The HPB has a complex polarization distribution, consisting of a vector radially polarized beam and a scalar circularly polarized beam in our experiment. These two kinds of beams have different directions of dead zones of external magnetic fields; thereby, the atomic magnetometer with an HPB can avoid the non-signal area when the direction of the external magnetic field is in the plane perpendicular to the light polarization plane. Furthermore, the optical magnetic resonance (OMR) signal using an HPB still has no dead zones even when the direction of the external magnetic field is in the plane parallel to the polarization plane in our scheme. Our work has the potential to simplify and optimize dead-zone-free atomic magnetometers.