Bai Zhengyang, Hang Chao, Huang Guoxiang
State Key Laboratory of Precision Spectroscopy and Department of Physics, East China Normal University, Shanghai 200062, China.
Opt Express. 2013 Jul 29;21(15):17736-44. doi: 10.1364/OE.21.017736.
We propose a scheme to design a new type of optical metamaterial that can mimic the functionality of four-state atomic systems of N-type energy-level configuration with electromagnetically induced transparency (EIT). We show that in such metamaterial a transition from a single EIT to a double EIT of terahertz radiation may be easily achieved by actively tuning the intensity of the infrared pump field or passively tuning the geometrical parameters of resonator structures. In addition, the group velocity of the terahertz radiation can be varied from subluminal to superluminal by changing the pump field intensity. The scheme suggested here may be used to construct chip-scale slow and fast light devices and to realize rapidly responded switching of terahertz radiation at room temperature.
我们提出了一种设计新型光学超材料的方案，该超材料能够通过电磁诱导透明（EIT）来模拟具有N型能级配置的四态原子系统的功能。我们表明，在这种超材料中，通过主动调节红外泵浦场的强度或被动调节谐振器结构的几何参数，可以轻松实现太赫兹辐射从单EIT到双EIT的转变。此外，通过改变泵浦场强度，太赫兹辐射的群速度可以从亚光速变化到超光速。这里提出的方案可用于构建芯片级的慢光和快光器件，并在室温下实现太赫兹辐射的快速响应开关。
