Ding Pei, Fan Chunzhen, Cheng Yongguang, Liang Erjun, Xue Qianzhong
Department of Mathematics and Physics, Zhengzhou Institute of Aeronautical Industry Management, Zhengzhou, China.
Appl Opt. 2012 Apr 20;51(12):1879-85. doi: 10.1364/AO.51.001879.
We demonstrate theoretically an analog of electromagnetically induced transparency (EIT) in the plasmonic metamaterial with the unit cell consisting of three parallel metallic rods. The electromagnetic mechanism for the EIT-like transmission is discussed based on our investigation of the localized surface plasmon resonances in three trirod configurations. We find that the transmission minima surrounding the transparency window on both sides correspond to two detuned magnetic resonances, which arise respectively from the antiphase plasmon couplings between a long rod and a short rod and between two short rods. A decrease of more than 10 times in the group velocity can be achieved for the trirod structure at the transparency window in the optical regime, and the EIT-like response can be well described by the theoretical model of two harmonic oscillators. This work not only reveals the EIT-like transmission in plasmonic metamaterial consisting of detuned magnetic "atoms," but also provides further insight into the plasmons' interactions, especially for metallic nanostructures comprising multiple metallic elements.
我们从理论上证明了在由三根平行金属棒组成的单元胞的等离激元超材料中存在电磁诱导透明（EIT）类似物。基于我们对三种三棒构型中局域表面等离激元共振的研究，讨论了类EIT传输的电磁机制。我们发现，透明窗口两侧围绕其的传输最小值对应于两个失谐的磁共振，它们分别源于长棒与短棒之间以及两根短棒之间的反相等离激元耦合。在光学波段的透明窗口处，三棒结构的群速度可降低超过10倍，并且类EIT响应可以用两个谐波振荡器的理论模型很好地描述。这项工作不仅揭示了由失谐磁性“原子”组成的等离激元超材料中的类EIT传输，还为等离激元的相互作用提供了进一步的见解，特别是对于包含多种金属元素的金属纳米结构。
