The noise analysis and multi-physical field coupling study of high-precision SERF atomic gyroscopes

The spin-exchange relaxation-free atomic gyroscope, with its exceptionally high theoretical precision, demonstrates immense potential to become the next-generation strategic-grade gyroscope. However, due to technological noise, there is still a significant gap between its actual precision and theoretical precision. This study identifies the key factor limiting the precision of the SERF gyroscope as coupling noise. By optimizing the detection loop structure, a distinction between the dual-axis signals' response to optical and magnetic fields was achieved—where the optical errors responded similarly, while the response to magnetic noise was opposite. Based on the differences in the optical-magnetic response of the dual-axis signals, empirical mode decomposition was used to decompose the dual-axis gyroscope signals into multiple intrinsic mode functions, and Allan deviation analysis was applied to analyze the noise characteristics of the intrinsic mode functions over various periods. This study successfully reveals that optical errors caused by thermal-optical coupling and long-period magnetic noise induced by thermal-magnetic coupling are the dominant factors limiting the long-term stability of the SERF gyroscope. Based on these analyses, the study concludes that to achieve strategic-grade precision for the SERF gyroscope, it is essential to effectively address the noise issues caused by multi-physical field couplings.