Suppression of the Bias Error Induced by Vapor Cell Temperature in a Spin-Exchange Relaxation-Free Gyroscope

Bias stability is one of the most important characteristics of a spin-exchange relaxation-free gyroscope (SERFG). The previous research on the SERFG has demonstrated that atomic density fluctuation induced by the vapor cell temperature fluctuations in a SERFG limits its bias stability. In this paper, a steady-state response model of a SERFG dependent on the vapor cell temperature is established, and a method to reduce the vapor cell temperature error of the SERFG is developed. By adjusting the vapor cell temperature, the SERFG can be tuned to a working point where the output signal is insensitive to the cell temperature fluctuation, i.e., the insensitive point, so that the bias error induced by cell temperature fluctuations can be effectively suppressed. The proposed method is verified by experiments, and experimental results are in good agreement with the model. By using the proposed method, SERFG drift was reduced from 0.051 deg/h to 0.028 deg/h without adjusting the wavelength of the probe laser. This study presents a way to improve the SERFG performance, which is of reference value for quantitative error analysis and miniaturization in atomic gyroscopes.