Bandwidth Expansion of Atomic Spin Gyroscope With Transient Response

Atomic spin gyroscopes (ASGs) have ultra-high sensitivity on inertial measurement, but the narrow bandwidth limits its application. We describe a bandwidth expansion method for ASG based on the transient response of electron spin. The gyroscope is modeled as a four inputs two outputs linear state-space system by commonly used linearization. As the transverse component of electron spin polarization decays much faster than that of nuclear spin, a quasi-steady-state approximation on electron spin is proposed to estimate the transverse polarization component of nuclear spin in real-time. In experiment, the system matrix, input matrix, and output matrix of the state-space model are decided with a series of calibrations. A bandwidth expansion method is proposed to solve the rotation input with the transient response of the electron spin. The proposed method shows strong rotation tracking ability compared with the steady-state method. The bandwidth of ASG is extended and 3 dB/Oct lower signal attenuation in the frequency range of 0.4-5 Hz is obtained with the proposed method.