激光参量对CPT铷原子钟稳定度影响的数值分析

Numerical Analysis of Influence of Laser Parameters on CPT Rb Clock Signals

为具体分析激光参量对相干布居囚禁(CPT)原子钟的稳定度性能的影响,在Λ-型三能级原子系统模型的基础上,采用半经典密度矩阵方法,数值模拟计算了不同激光参量对CPT铷原子钟共振谱线信号的影响,并给出了比较分析。结果显示:两束激光强度的不对称对CPT钟信号强度的影响很大,而激光频率失谐对CPT钟信号影响较小;此外,当激光强度不对称与频率失谐同时存在时,荧光信号谱出现不对称,微波辐射信号发生频移。

Based on the model of the A-type three-level atomic system, the impact of laser parameters on the CPT signals of rubidium atomic clock is analyzed by using the semi-classical density matrices approach in order to make a concrete analysis of the influence of laser parameters upon the stability performance of the CPT （coherent population trapping） atomic clock, and the comparison is presented. The results show that the signal intensity of the CPT clock significantly varies with the intensity symmetry of the laser beams. In contrast, the influence of the frequency detuning is not important for the clock signal. In addition, when the laser intensity asymmetry and frequency detuning exist together, the asymmetry of the CPT fluorescence spectrum and the frequency shift of the CPT microware signal would occur.