Subluminal and superluminal terahertz radiation in metamaterials with electromagnetically induced transparency.
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.
State Key Laboratory of Precision Spectroscopy and Department of Physics, East China Normal University, Shanghai 200062, China.
Zhengyang
Z
Bai
Chao
C
Hang
Guoxiang
G
Huang
D003198:Computer Simulation; D017076:Computer-Aided Design; D004574:Electromagnetic Fields; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008420:Manufactured Materials; D008962:Models, Theoretical; D012031:Refractometry / Q000295:instrumentation*; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D055053:Terahertz Radiation