Diffusion-pumping-based atomic magnetometer with enhanced adaptability to variations in optical parameters

Spin-Exchange Relaxation-Free (SERF) atomic magnetometers (AMs) have shown great potential in recent years, with growing interest in linewidth narrowing and light shift suppression to further enhance their performance. However, the pump light in SERF AMs introduces increased linewidth and light shift. By exploiting diffusion effect to polarize alkali atoms, these detrimental effects can be significantly mitigated. In this study, we performed simulations of the spatial distribution of electron polarization under diffusion effects, analyzing the impact of aperture size and pump rate on the spatial distribution, which is beneficial for parameter optimization. Experimental results show significant linewidth reduction and the slope of linewidth variation versus optical power in diffusion pumping method is only 1.5% of that in pump–probe overlapping mode. Additionally, the fictitious magnetic field is greatly suppressed, with its overall magnitude reduced by 89%. Systematic tests further confirm that the proposed AM exhibits improved response stability compared to the pump–probe overlap configuration. Additionally, under frequency detuning and without real-time field compensation, the diffusion pumping magnetometer exhibits a larger scale factor than conventional designs. Our configuration provides a reliable solution for the development of high-performance AMs, especially for array-based configurations.