Department of Physics, Indian Institute of Technology Kanpur 208016, India.
Opt Lett. 2009 Dec 1;34(23):3728-30. doi: 10.1364/OL.34.003728.
We theoretically demonstrate control of the plasmalike effective response of a metamaterial composed of aligned metallic nanorods when the electric field of the incident radiation is parallel to the nanorods. By embedding this metamaterial in a coherent atomic/molecular medium, for example, silver nanorod arrays submerged in sodium vapor, we can make the metamaterial transmittive in the forbidden frequency region below its plasma frequency. This phenomenon is enabled by having Lorentz absorbers or other coherent processes in the background medium, which provide a large positive dielectric permittivity in the vicinity of the resonance, thereby rendering the effective permittivity positive. In particular, processes such as electromagnetically induced transparency are shown to provide additional control to switch and tune the new transmission bands.
我们从理论上证明了当入射辐射的电场与纳米棒平行时，排列整齐的金属纳米棒组成的超材料的等离子体等效响应可以得到控制。例如，将这种超材料嵌入相干原子/分子介质中，即浸没在钠蒸气中的银纳米棒阵列中，我们可以使超材料在低于等离子体频率的禁带区域具有透过性。这种现象是通过在背景介质中具有洛伦兹吸收器或其他相干过程来实现的，这些过程在共振附近提供了较大的正介电常数，从而使有效介电常数为正。具体来说，电磁感应透明等过程被证明可以提供额外的控制，以切换和调整新的传输带。
