中国物理B ›› 2023, Vol. 32 ›› Issue (3): 30701-030701.doi: 10.1088/1674-1056/ac81b1

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Suppression of laser power error in a miniaturized atomic co-magnetometer based on split ratio optimization

Wei-Jia Zhang(张伟佳)1, Wen-Feng Fan(范文峰)1,2,†, Shi-Miao Fan(范时秒)1,2, and Wei Quan(全伟)2   

  1. 1 School of Instrumentation Science and Opto-electronics Engineering, Beihang University, Beijing 100190, China;
    2 Beihang Hangzhou Innovation Institute Yuhang, Xixi Octagon City, Yuhang District, Hangzhou 310023, China
  • 收稿日期:2022-06-09 修回日期:2022-07-13 接受日期:2022-07-18 出版日期:2023-02-14 发布日期:2023-02-21
  • 通讯作者: Wen-Feng Fan E-mail:fanwenfeng@buaa.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61925301 and 62103026).

Suppression of laser power error in a miniaturized atomic co-magnetometer based on split ratio optimization

Wei-Jia Zhang(张伟佳)1, Wen-Feng Fan(范文峰)1,2,†, Shi-Miao Fan(范时秒)1,2, and Wei Quan(全伟)2   

  1. 1 School of Instrumentation Science and Opto-electronics Engineering, Beihang University, Beijing 100190, China;
    2 Beihang Hangzhou Innovation Institute Yuhang, Xixi Octagon City, Yuhang District, Hangzhou 310023, China
  • Received:2022-06-09 Revised:2022-07-13 Accepted:2022-07-18 Online:2023-02-14 Published:2023-02-21
  • Contact: Wen-Feng Fan E-mail:fanwenfeng@buaa.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61925301 and 62103026).

摘要: A miniaturized atomic spin-exchange relaxation-free (SERF) co-magnetometer measures angular velocity using a balanced polarimetry technique which is easily affected by the laser power. A laser power closed-loop control system is usually used to suppress the fluctuation of the laser power. Although this method can greatly eliminate the fluctuation of the in-loop laser power (the feedback laser), it cannot fully eliminate the fluctuation of the out-of-loop laser power (the signal measurement laser). This leads to SERF gyroscope laser power error, which reduces the inertial measurement accuracy. In this paper, the influence mechanism of the split ratio (the ratio of the in-loop laser power to the out-of-loop laser power) on the out-of-loop laser power control accuracy is analyzed by establishing a laser power transmission model inside and outside the loop. Moreover, a method is developed to improve the out-of-loop laser power stability by optimizing the split ratio. Comparative experiments showed that the relative Allan standard deviation of the out-of-loop laser power decreased from 5.48×10-6 to 2.62×10-6 at 100 s, and decreased by an order of magnitude from 1.76×10-5 to 3.30×10-6 at 1000 s. Correspondingly, the rate ramp coefficient in the Allan standard deviation curve of the SERF gyroscope test data decreased from 1.312 [(°/h)/h] to 0.246 [(°/h)/h]. And the bias stability increased from 0.032 °/h to 0.019 °/h. Therefore, the proposed method can improve the long-term stability of the probe laser power and effectively suppress the laser power error of the SERF gyroscope.

关键词: atomic gyroscope, spin-exchange relaxation-free, laser power stability, error suppression

Abstract: A miniaturized atomic spin-exchange relaxation-free (SERF) co-magnetometer measures angular velocity using a balanced polarimetry technique which is easily affected by the laser power. A laser power closed-loop control system is usually used to suppress the fluctuation of the laser power. Although this method can greatly eliminate the fluctuation of the in-loop laser power (the feedback laser), it cannot fully eliminate the fluctuation of the out-of-loop laser power (the signal measurement laser). This leads to SERF gyroscope laser power error, which reduces the inertial measurement accuracy. In this paper, the influence mechanism of the split ratio (the ratio of the in-loop laser power to the out-of-loop laser power) on the out-of-loop laser power control accuracy is analyzed by establishing a laser power transmission model inside and outside the loop. Moreover, a method is developed to improve the out-of-loop laser power stability by optimizing the split ratio. Comparative experiments showed that the relative Allan standard deviation of the out-of-loop laser power decreased from 5.48×10-6 to 2.62×10-6 at 100 s, and decreased by an order of magnitude from 1.76×10-5 to 3.30×10-6 at 1000 s. Correspondingly, the rate ramp coefficient in the Allan standard deviation curve of the SERF gyroscope test data decreased from 1.312 [(°/h)/h] to 0.246 [(°/h)/h]. And the bias stability increased from 0.032 °/h to 0.019 °/h. Therefore, the proposed method can improve the long-term stability of the probe laser power and effectively suppress the laser power error of the SERF gyroscope.

Key words: atomic gyroscope, spin-exchange relaxation-free, laser power stability, error suppression

中图分类号:  (Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing)

  • 07.07.Df
07.55.Ge (Magnetometers for magnetic field measurements) 42.79.-e (Optical elements, devices, and systems)