SERF 原子自旋惯性测量检测误差分析及抑制

The performance of the probe system is the key factor to determine the sensitivity and stability limit of the spin-exchange relaxation-free (SERF) atomic spin co-magnetometer for inertial measurement. In order to suppress the low-frequency random noise in SERF auto spin co-magnetometer, the error mechanism model for the probe system is established based on the steady-state solution of transverse electron spin polarization and optical rotation angle. The main factors affecting the output signal of the probe system are clarified. According to model analysis, the initial probe light intensity incident on the vapor cell as the signal background directly causes the fluctuation of the scale coefficient rather than the electron spins. In addition, the non-ideal linear polarization of probe light affects the electron spins in a transverse pumping manner and causes a light shift, both of which can cause measurement error. Aiming at the main parameters affecting the noise, the optimization path has been proposed. The probe light frequency has been first optimized to increase the scale coefficient of inertial measurement. Then the transverse pumping rate, light shift, and background fluctuation have been reduced by optimizing the probe light intensity. According to the analysis of Allan variance, the bias instability of SERF auto spin co-magnetometer is suppressed by 1.8 times, and the coefficients of rate ramp are reduced from 0.124 (º)/h² to 0.041 (º)/h². Therefore, the effect of reducing the low-frequency random noise in the output signal is achieved.