准Λ型四能级原子系统在弱场中的增益及电磁感应透明

利用数值模拟的方法讨论了稳态下准型四能级原子与两光场相互作用系统对探测场的增益以及与粒子数布居规律之间的关系。结果表明即使在场较弱的情况下,随着探测场和它所对应能级间跃迁频率失谐量的变化,系统在所有拉比频率相位为零时对探测光总会同时呈现三个增益峰和两个固定的产生电磁感应透明(EIT)现象的位置,并且当系统呈现电磁感应透明的同时,探测场所对应的高能级粒子数为零;而拉比频率相位的变化则会导致系统对探测光既有吸收也有增益,并且也呈现电磁感应透明现象,但仅仅相位的变化并不影响高能级的粒子数分布。值得注意的是该结果均在精确求解下所得。

Electromagnetically Induced Transparency of Quasi-A-Type Four-Level Atom System at Low-Light Levels

The probe field gain and its relation with the population rule in high level in the quasiΛtype fourlevel atom system interacting with two light fields at low-light levels under stable state are numerically investigated. It is found that, even for low-light level, with the variation of probe field and the relevant frequency dteuning of interlevel transition, the system always displays three gain peaks for probe field simultaneously and two fixed positions where the electromagnetically induced transparency (EIT) is observed, when all phases of Rabi frequencies are zero. When the system displays EIT, the probe field related population in the high level is zero. When the phase of Rabi frequency is changed, gain and absorption for the probe field occur, EIT phenomenon also exists, but the phase change cannot influence the population in the high level alone. It is worth noting that all results are achieved without any approximation.