环形四能级负折射率原子系统

Negative Refractive Index in a Closed Four-level Atomic System

提出一个闭合的四能级原子系统,利用量子相干技术使介质具备左手材料特性(负折射率),考虑旋转波近似以及在高密气体中的局域场效应,利用密度矩阵方法进行理论计算,数值模拟结果表明,介质同时在两个可见光频率区域内实现了负折射率,通过调节控制场强度可改变负折射率的频率范围.

A closed four-level system in atomic vapor was proposed, which was made to possess left handedness by means of the technique of quantum coherence. The density matrix method was utilized in view of the rotating-wave approximation and the local-field effect in high dense gas. The conclusion of the numerical simulation shows that the medium can simultaneously exhibits left handedness in two visible frequency bands, and one can manipulate the width of the frequence bands by changing the intensity of the control field.