四能级原子系统中的电磁诱导吸收

以三个电偶极跃迁(中间跃迁作为探测跃迁、两边分别是耦合跃迁和控制跃迁)构成N型四能级系统为例，研究介质对探测光的吸收.揭示了在N型四能级系统中，既可产生电磁诱导吸收又可产生电磁诱导透明.这不仅取决于非相干转移率的大小，而且还取决于耦合场、控制场的强度和第四个简并能级的衰减速率大小. 关键词： 电磁诱导吸收 电磁诱导透明 原子相干的自发转移 能级的衰减速率

Electromagnetically induced absorption in four-level atomic system

A four-level atomic system is employed as an example, in which three transitions are in N configuration and the middle transition is used as a probe transition. We show that electromagnetically induced absorption and electromagnetically induced transparency can appear in the four-level N-type atomic system, which are dependent not only on the spontaneous transfer of atomic coherence, but also on the relaxation of the fourth level, the Rabi frequency of the coupling and the control field.