IEEE Sensors Journal

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

Feng Liu, Lihong Duan, Wenfeng Fan, Haoying Pang, Sixun Liu, Wei Quan

Published Dec 27, 2021• 24 citations

Abstract

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.

DOI: 10.1109/jsen.2021.3138831

Related papers

Suppression of the vapor cell temperature error in a spin-exchange relaxation-free comagnetometer

Jiali Liu, Liwei Jiang, Chi Fang +2 more

Abstract The fluctuation of the vapor cell temperature leads to the variations of the density of the alkali metal atoms, which seriously damages the long-term stability of the spin-exchange relaxation-free (SERF) comagnetometer. To address this problem, we propose a novel method for suppressing the cell temperature error by manipulating the probe laser frequency. A temperature coefficient model of the SERF comagnetometer is established based on the steady-state response, which indicates that the comagnetometer can be tuned to a working point where the output signal is insensitive to the cell temperature fluctuation, and the working point is determined by the relaxation rate of the alkali metal atoms. The method is verified in a K−Rb− 21Ne comagnetometer, and the experimental results are consistent with the theory. The theory and method presented here lay a foundation for the practical applications of the SERF comagnetometer.

Chinese Physics BOct 9, 20244 citations

Suppression of vapor cell temperature error for spin-exchange-relaxation-free magnetometer

Jixi Lu, Zheng Qian, Jiancheng Fang +1 more

This paper presents a method to reduce the vapor cell temperature error of the spin-exchange-relaxation-free (SERF) magnetometer. The fluctuation of cell temperature can induce variations of the optical rotation angle, resulting in a scale factor error of the SERF magnetometer. In order to suppress this error, we employ the variation of the probe beam absorption to offset the variation of the optical rotation angle. The theoretical discussion of our method indicates that the scale factor error introduced by the fluctuation of the cell temperature could be suppressed by setting the optical depth close to one. In our experiment, we adjust the probe frequency to obtain various optical depths and then measure the variation of scale factor with respect to the corresponding cell temperature changes. Our experimental results show a good agreement with our theoretical analysis. Under our experimental condition, the error has been reduced significantly compared with those when the probe wavelength is adjusted to maximize the probe signal. The cost of this method is the reduction of the scale factor of the magnetometer. However, according to our analysis, it only has minor effect on the sensitivity under proper operating parameters.

Review of Scientific InstrumentsAug 1, 201533 citations

Low drift nuclear spin gyroscope with probe light intensity error suppression*

Wenfeng Fan, Wei Quan, Feng Liu +2 more

A nuclear spin gyroscope based on an alkali-metal–noble-gas co-magnetometer operated in spin-exchange relaxation-free (SERF) regime is a promising atomic rotation sensor for its ultra-high fundamental sensitivity. However, the fluctuation of probe light intensity is one of the main technical error sources that limits the bias stability of the gyroscope. Here we propose a novel method to suppress the bias error induced by probe light intensity fluctuations. This method is based on the inherent magnetic field response characteristics of the gyroscope. By the application of a bias magnetic field, the gyroscope can be tuned to a working point where the output signal is insensitive to probe light intensity variation, referred to herein as ‘zero point’, thus the bias error induced by intensity fluctuations can be completely suppressed. The superiority of the method was verified on a K–Rb–21Ne co-magnetometer, and a bias stability of approximately 0.01 °/h was obtained. In addition, the method proposed here can remove the requirement of the closed-loop control of probe light intensity, thereby facilitating miniaturization of the gyroscope volume and improvement of reliability.

Chinese Physics BSep 18, 201921 citations

Suppression of Low-Frequency Magnetic Drift Based on Magnetic Field Sensitivity in K-Rb-21Ne Atomic Spin Comagnetometer

Ye Liu, Wenfeng Fan, Yang Fu +3 more

A spin-exchange relaxation-free comagnetometer is a promising high-precision gyroscope as its inertial measurement sensitivity can rival that of existing technologies. The magnetic field error is one of the main factors that limits the long-term stability of the comagnetometer. The steady-state response and frequency response models of a K-Rb-21Ne comagnetometer are modified by considering the spin-exchange rate between the electron spins and the nuclear spins. The modified models are used to redefine the bias magnetic sensitivity of the K-Rb-21Ne comagnetometer and the suppression method of low-frequency magnetic field error is proposed. We demonstrate the magnetic drift suppression method proposed in the article by optimizing the cell temperature and pump laser power density. This study is helpful to improve the rotation measurement performance of the K-Rb-21Ne comagnetometer.

IEEE Transactions on Instrumentation and MeasurementJan 1, 202219 citations

Effects of pump laser intensity on the cell temperature working point in a K-Rb- 21 Ne spin-exchange relaxation-free co-magnetometer

Jiasen Ruan, Lihong Duan, Yang Fu +2 more

The cell temperature working point optimization of the spin-exchange relaxation-free (SERF) co-magnetometer is studied theoretically and experimentally in this article. Based on the steady-state solution of the Bloch equations, the steady-state response model of the K-Rb- 21 Ne SERF co-magnetometer output signal with cell temperature is established in this paper. And combined with the model, a method to find the optimal working point of the cell temperature that incorporates the pump laser intensity is proposed. The scale factor of the co-magnetometer under different pump laser intensities and cell temperatures is obtained experimentally, and the long-term stability of the co-magnetometer at the different cell temperatures with corresponding pump laser intensities is measured. The results show that the bias instability of the co-magnetometer is reduced from 0.0311 deg/h to 0.0169 deg/h by obtaining the optimal working point of the cell temperature, which verifies the validity and accuracy of the theoretical derivation and the proposed method.

Optics ExpressFeb 6, 202311 citations

Suppression of thermal coupling noise in the SERF atomic co-magnetometer

Jiasen Ruan, Lihong Duan, Yang Fu +4 more

Heating the alkali metal vapor cell to obtain high atomic density is a prerequisite for realizing the high-precision measurement for spin-exchange relaxation-free (SERF) co-magnetometer. However, the thermo-magnetic and thermo-optical coupling noise caused by the temperature diffusion from the alkali vapor cell is one of the main factors restricting the co-magnetometer performance at present. Here the influence of heating on the SERF co-magnetometer was comprehensively studied, and the thermal error model of the system was established. A novel heat insulation structure for the co-magnetometer was designed, and the effectiveness was verified through monitoring of characteristic temperature points. Compared to the conventional oven support, the average maximum temperature difference within 12 h of the optical path and magnetic shielding systems (OPMSS) decreased by 52%, the bias instability of the co-magnetometer decreased by 24%, and the noise of the co-magnetometer at 1 Hz decreased by 33%. The experimental results demonstrate that this method reduces the temperature fluctuation of the OPMSS, effectively suppresses the thermal coupling noise, and thus improves the performance of the SERF co-magnetometer. Moreover, this method is also applicable to other quantum sensors based on alkali metal vapor cell.

Results in PhysicsSep 22, 202314 citations