摘要
基于非线性磁光旋转(nonlinear magneto-optical rotation,NMOR)效应的铷原子磁力仪通过特定时长的自由弛豫正弦振荡信号可获得拉莫尔进动频率和外磁场值,因此自由弛豫信号的截取时长能够影响原子磁力仪的性能指标。重点研究了在500 nT背景磁场条件下自由弛豫信号截取时长对原子磁力仪灵敏度和磁场测量值的影响。测量结果表明,用噪声功率谱方法标定的灵敏度指标随着自由信号截取时长的增加逐渐减小并趋于稳定,约0.2 pT/Hz1/2;交变磁场实验表明该磁力仪所得的磁场值是特定截取时长内磁场波动的平均。因此本文NMOR原子磁力仪所得的高灵敏度指标一定程度上是通过数学方法平均了自由弛豫信号截取时长内的磁场值波动。该方法对其他原子磁力仪或实验装置灵敏度的标定和磁场测量值的分析具有一定的借鉴意义。
The rubidium atomic magnetometer based on nonlinear magneto-optical rotation(NMOR)effect can obtain the Larmor frequency and external magnetic field value through the free relaxation sinusoidal oscillation signal with specific time length,thus,intercept-length of relaxation signal can affect the performance of the atomic magnetometer.In this paper,the influence of the interception time of the free relaxation signal on the sensitivity and the measured magnetic field was studied near the background magnetic field of 500 nT.The measurement results show that the sensitivity calibrated by the noise power spectrum decreases gradually and reaches a stable value of 0.23 pT/Hz1/2with the increase of the interception time,the measurement of the alternating magnetic field shows that the field values measured according to the free relaxation signals with long interception-length represent the average results.Therefore,the high sensitivity index of the NMOR atomic magnetometer in this paper is obtained to some extent through mathematical processing to average the fluctuation of the magnetic field value.This method can be used for reference to calibrate the sensitivity of other atomic magnetometers or experimental devices and analyze the measured magnetic field values.
作者
杨宝
崔敬忠
缪培贤
杨世宇
客洪亮
涂建辉
冯浩
Yang Bao;Cui Jingzhong;Miao Peixian;Yang Shiyu;Ke Hongliang;Tu Jianhui;Feng Hao(Science and Technology on Vacuum and Physics Laboratory,Lanzhou Institute of Physics,Lanzhou 730000,China)
出处
《电子测量与仪器学报》
CSCD
北大核心
2020年第1期97-104,共8页
Journal of Electronic Measurement and Instrumentation
关键词
原子磁力仪
非线性磁光旋转
灵敏度
磁场测量值
atomic magnetometer
nonlinear magneto-optical rotation
sensitivity
magnetic field measurement
