参数振荡原子磁强计自旋演化的分析与仿真

Analysis and Simulation of Spin Evolution of Parametric Oscillating Atomic Magnetometer

原子磁强计当前已经成为磁场检测最灵敏的传感器,逐步在很多科研、工程领域得到了应用。参数振荡原子磁强计作为一种可以测量横向磁场的双轴磁强计有着其独特的应用领域。本文以布洛赫方程为基础,以提高参数振荡原子磁强计系统的灵敏度为目标,通过理论分析和建模仿真的方式对参数振荡原子磁强计信号响应及信号处理环节进行了研究,可以为实验时高灵敏度信号参数的优化提供依据。基于仿真模型,通过改变磁场调制深度和扫描解调相位得到测量信号的响应曲线,还可以用于检验理论分析过程中模型近似的有效性,完成实验过程中一些非理想的情况如主磁场与光场存在夹角、作用磁场同主磁场不正交时的信号特征的定量分析。

Objective Atomic magnetometer has become the most sensitive sensor for magnetic field detection,and has been gradually applied in many scientific research and engineering fields.As a biaxial magnetometer which can measure the transverse magnetic field,the parametric oscillating atomic magnetometer has its unique application field.In order to improve the sensitivity of the parametric oscillating atomic magnetometer system,this paper mainly studies the influence of different parameters on the magnetic field measurement of the parametric oscillating atomic magnetometer.Method Starting from the Bloch equation,the signal response and signal processing of the relevant parameters of the parametric oscillating atomic magnetometer are studied by means of simulation modeling and theoretical reasoning,which can provide a basis for optimization high sensitivity signal parameters in the experiment.Results and Discusions Based on the simulation model,the response curve of the measured signal is obtained by varying the modulation depth of the magnetic field and scanning the demodulation phase.After comparison,it is found that the theoretical and simulation results are stable.Through analysis,it can be concluded that when different parameter values are given,the sensitivity of the system signal will also have different changes.Some specific parameter values obtained from the conclusion can provide a basis for the optimization of high sensitivity signal parameters in the experiment.Conclusion In addition,based on the simulation model,the validity of the model approximation in the theoretical analysis process can be verified,and the experimental system can also be analyzed in more detail.In the next step,the difference between theoretical analysis and numerical simulation can also reflect the changes brought by the approximate treatment in the theoretical analysis.On this basis,the noise and parameters of the system can be optimized.The method of numerical simulation is further useful for identifying the rules of the parametric oscillating atomic magnetometer,the analysis of noise,the sensitivity of the magnetometer,and the random walk of the gyro angle.In addition,the numerical simulation can also complete the quantitative analysis of the signal characteristics in some non-ideal situations in the experimental process,such as the angle between the main magnetic field and the light field,and when the acting magnetic field is not orthogonal to the main magnetic field.