Optical characteristics associated with magnetic resonance in toroidal metamaterials of vertically coupled plasmonic nanodisks
Optical characteristics associated with magnetic resonance in toroidal metamaterials of vertically coupled plasmonic nanodisks
复制标题
垂直耦合等离子体纳米盘环形超材料中与磁共振相关的光学特性
DOI：
10.1364/josab.31.001103
复制
发表时间：
2014-05
影响因子：
1.9
通讯作者：
Wang, Sheng Lei
中科院分区：
文献类型：
--
作者：
Zhang, Qiang;Xiao, Jun Jun;Wang, Sheng Lei
超材料中的磁共振基本上是由光学感应电流环形成的，当按特定顺序排列时，可以显示出奇异的特征。在这项工作中，我们数值研究了强耦合等离子体纳米盘中与磁共振相关的光学特性，它被证明支持垂直极化(盘面外的电场)的各种磁共振。为了识别这些本质上与光感应电流环相关的模式，我们计算了光谱、多极矩的辐射功率和共振磁场模式。结果表明，最低阶共振态依次为磁偶极子模、磁四极子模和环形模。对这些模式的表面电荷密度、感应电流密度和磁场近场进行了仔细的考察，结果表明，这些模式在光谱和真实空间中的位置有很大的不同，具有明显的对称性。有鉴于此，我们在圆盘上引入了一个同心和非同心的气孔，作为一个小的微扰，来调节它们的共振。结果表明，气孔的半径和位置都可以改变谐振频率。然而，有趣的是，它们对模式顺序的影响是不同的。这些结果为调节双圆盘结构超材料的光学性质提供了一种有用的方法。
Magnetic resonance in metamaterials is basically formed by an optically induced current loop that, when arranged in a specific order, can exhibit exotic features. In this work, we numerically study the magnetic-resonance-associated optical characteristics in strongly coupled plasmonic nanodisks, which are shown to support various magnetic resonances for vertical polarization (E-field out of the disk plane). To identify these modes, which are essentially relevant to the optically induced current loops, we calculate the optical spectrum, the radiation powers from multipole moments, and the resonant magnetic field pattern. It is shown that the lowest-order resonances are sequentially magnetic dipole mode, magnetic quadrupole mode, and toroidal mode. The surface charge density, the induced current density, and the magnetic near-field are carefully examined for these modes, which show that these modes are quite differently located in both spectrum and real space, bearing distinct symmetry nature. In view of that, we introduce a concentric and nonconcentric air hole in the disks, as a small perturbation, to tune their resonance. It is found that both the radii of the air hole and its position are capable to shift the resonant frequencies. However, their impacts are interestingly distinct with respect to the mode order. These results can provide a useful way to adjust the optical properties of the metamaterials constructed by double disks.
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影响因子：
4
作者：
Dong, Zheng-Gao;Zhu, J.;Zhang, X.
通讯作者：
Zhang, X.
影响因子：
3.8
作者：
Q. Zhang;J. Xiao;X. Zhang;Y. Yao;H. Liu
通讯作者：
Q. Zhang;J. Xiao;X. Zhang;Y. Yao;H. Liu
DOI：
10.1109/eucap.2014.6902488
发表时间：
2013-03
期刊：
The 8th European Conference on Antennas and Propagation (EuCAP 2014)
影响因子：
--
作者：
J. Greffet
通讯作者：
J. Greffet
影响因子：
64.8
作者：
通讯作者：
--
DOI：
10.1364/josab.27.001680
发表时间：
2010-08
影响因子：
1.9
作者：
A. Pors;M. Willatzen;O. Albrektsen;S. Bozhevolnyi
通讯作者：
A. Pors;M. Willatzen;O. Albrektsen;S. Bozhevolnyi