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

作　　者：张伟佳 范文峰 范时秒 全伟 Wei-Jia Zhang;Wen-Feng Fan;Shi-Miao Fan;Wei Quan(School of Instrumentation Science and Opto-electronics Engineering,Beihang University,Beijing 100190,China;Beihang Hangzhou Innovation Institute Yuhang,Xixi Octagon City,Yuhang District,Hangzhou 310023,China)

机构地区：[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

出　　处：《Chinese Physics B》2023年第3期180-186,共7页中国物理B（英文版）

基　　金：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)at1000 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 

分 类 号：TM937[电气工程—电力电子与电力传动]