提出一个原子蒸气中的四能级系统,能够实现左手材料特性(负折射率)。采用非相干抽运场来控制各能级上的粒子数布居,使探测场的电场分量和磁响应场分量被同时放大,避免了介质对探测场的强吸收。理论模拟计算表明抽运场的抽运率和相干耦合场的强度都能影响左手材料的负折射率频带。

An electromagnetically induced left-handedness scheme in atomic vapor medium is proposed. By applying an incoherent pump field to manipulate the populations in each level,the electric part and the magnetic part of the probe field are simultaneously amplified instead of strong absorption. It is shown that both the pumping rate of pump field and the intensity of the coupling field can affect the frequency band of negative refractive index of left-handed material (LHM).