Effect of optical polarization error on the magnetic resonance signal of NMOR atomic magnetometer

Abstract In NMOR magnetometers, we choose the linear polarized light to pump atoms, and the polarization state is the key factor affecting the evolution of alkali metal atoms. However, polarization errors are introduced due to the refraction of the glass surfaces of the cell and the imperfection of optical devices, which causes the actual laser light to be elliptically polarized. In this paper, the optical ellipticity for this system is accurately measured by the π transition principle first. Then, the magnetic resonance signals under different ellipticity are investigated theoretically and experimentally, and the atomic polarization state is visualized. The results show that the optical ellipticity error introduced by the system will reduce the measurement accuracy and sensitivity of the system, and it is meaningful to use high extinction ratio optical devices and introduce the quarter-wave plate to offset the circularly polarized components.