A measurement method of transverse light-shift in atomic spin co-magnetometer

We disclose a method to obtain the transverse light-shift along the probe light of a single-axis alkali metal-noble gas co-magnetometer. The relationship between transverse compensating field and light-shift is deduced through the steady-state solution of Bloch equations. The variety of probe light intensity is used to obtain the residual magnetic field, and step modulation tests are applied to acquire the total spin-relaxation rate of electron spins and self-compensation point. The transverse light-shift can be calculated by these parameters, and it is reduced from − 0.115 to − 0.039 nT by optimizing the probe light wavelength. Finally, long-term static test for a K-Rb-²¹Ne co-magnetometer has been performed. The bias instability of about 0.009 deg/h and rate ramp coefficient of 0.096 (deg/h)/h have been achieved to prove the improvement of stability.