Analysis of heading errors in pulsed mode and continuous mode all-optical Atomic Magnetometers

Atomic magnetometers based on alkali-metal isotopes commonly experience heading errors, which can be expressed as a function of the azimuth and polar angles of atomic spin orientation with respect to the total magnetic field direction. The heading errors are therefore major challenges in magnetometer applications, such as magnetic anomaly detection. Nonlinear Zeeman splitting and differences in Zeeman resonances between hyperfine ground states cause fundamental heading errors. In addition to these fundamental heading errors, fictitious heading errors can also be introduced during signal processing. In this work, we analyze heading errors resulting from changes in the temporal profile of free induced decay in a pulsed-mode all-optical magnetometer. Additionally, based on our group's previous work, we compare these errors with the heading errors in a continuous-mode all-optical atomic magnetometer, which arise from phase shift between optical pumping beam modulation and atomic spin rotation.