四能级原子系统中电磁感应吸收的相位控制

在以三个电偶极跃迁构成简并N型四能级系统中,利用密度矩阵方程计算了介质对探测场的吸收,研究了激光场拉比相位对吸收的影响.结果表明:介质对探测场的吸收和放大取决于控制场和信号场的拉比相位,且吸收和放大随控制场、信号场的拉比相位改变而作周期性变化,周期为2π;而探测场的拉比相位变化对吸收没有影响.同时,控制场、信号场拉比相位对吸收的影响是相同的,而且拉比相位主要影响原子相干,对原子布居影响不大.

Phase control of electromagnetically induced absorption in four-level atomic system

In this paper, we have calculated the absorption of the probing field in a N-type four-level atomic system with three dipole transitions using density matrix equation. The results indicate that the absorption or amplification of the probing field depends on the Rabi phases of the control field and signal field under introducing laser field Rabi phase, and the absorption or amplification periodically changes with the Rabi phases of the control field and the signal field at a period of 2π. The Rabi phase change of the probe field has no effect on the absorption. In addition, the effect of the signal field Rabi phase on absorption is the same as that of the control field Rabi phase on absorption. Rabi phase has an effect mainly on atomic coherence but little on atomic population.