啁啾场作用下二能级原子跃迁的时域动态变化分析

Dynamic analysis of temporal evolution of atomic transition in a two-level system under the frequency-chirped field

运用密度矩阵运动方程,分析了啁啾脉冲光场作用下二能级原子系统跃迁随时间的变化过程,并利用布洛赫矢量模型方法对其演化过程进行了动态分析.结果表明,啁啾效应使系统粒子布居几率出现振荡.布洛赫矢量演化过程表明,粒子布居几率的这种振荡,反映了系统粒子数转移、色散和吸收三者之间动态变化的物理过程.

The temporal evolution of atomic transition in a two-level system under the frequencychirped pulse field and its dynamic analysis are discussed respectively by means of the density matrix equation and the method of Bloch vector model. The result shows that the population probability oscillates in time domain under the effects of frequency-chirped pulse. The dynamic evolution process of the Bloch vector indicates that the oscillation of the population probability reflects the physical transformation process among the population transfer, dispersion and absorption in the system.