Fig. 1. Schematic of the closed-loop atomic spin polarization detection system. EOAM, electro-optic amplitude modulator; CO, coupler; PL, polarizer; λ/2, half-wave plate; PBS, polarizing beam splitter; PD, photodiode.

Fig. 2. Experimental setup of SERF co-magnetometer. TA, tapered amplifier; λ/4, quarter-wave plate; GL, Glan–Taylor prism.

Fig. 3. Testing of co-magnetometer angular velocity signal and scale factor based on closed-loop EOAM modulation detection system.

Fig. 4. Response testing of the closed-loop detection system to external perturbation. Case A: Using EOAM modulation only, with the closed-loop control system output turned off. Case B: The closed-loop EOAM modulation detection system designed in this Letter.

Fig. 5. Comparison of inertial measurement sensitivity among different detection methods.