利用微扰法分析两个相互耦合的参量四波混频过程

利用微扰法在旋转波近似下分析了铷原子中两个独立的参量四波混频过程和一个耦合的参量四波混频过程.当用超短激光脉冲相干激发这两个参量四波混频过程时,两个过程就会同时出现并且存在相互耦合作用.微扰分析表明,耦合的参量四波混频信号中可以观察到量子拍,量子拍幅度的大小不仅取决于超短脉冲的特性,而且依赖于两个耦合的参量四波混频过程中的相位匹配.

Analysis of Two Coupled Parametric Four-Wave-Mixing Processes Using Perturbative Theory

Two parametric four-wave-mixing (FWM) processes in Rb atoms are studied using perturbation theory under the condition of rotating wave approximation.The two parametric FWM processes are coupled when they are excited coherently by a short laser pulse with a bandwidth encompassing the two corresponding upper energy levels in the two FWM processes.Perturbative analysis reveals clear evidence of the appearance of quantum beatings in the two coupled parametric FWM signals.The amplitude of the quantum beating is not only determined by the temporal and spectral properties of the pump laser pulses,but also influenced by the phase-matching conditions for the two coupled parametric FWM processes.