Lee S C, Kang J H, Park Q-H, Krishna S, Brueck S R J
Center for High Technology Materials and Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM 87106, USA.
Department of Physics, Korea University, Seoul 136-701, Korea.
Sci Rep. 2016 Apr 19;6:24400. doi: 10.1038/srep24400.
The electric field immediately below an illuminated metal-film that is perforated with a hole array on a dielectric consists of direct transmission and scattering of the incident light through the holes and evanescent near-field from plasmonic excitations. Depending on the size and shape of the hole apertures, it exhibits an oscillatory decay in the propagation direction. This unusual field penetration is explained by the interference between these contributions, and is experimentally confirmed through an aperture which is engineered with four arms stretched out from a simple circle to manipulate a specific plasmonic excitation available in the metal film. A numerical simulation quantitatively supports the experiment. This fundamental characteristic will impact plasmonics with the near-fields designed by aperture engineering for practical applications.
在电介质上有孔阵列的照明金属膜正下方的电场，由入射光通过孔的直接透射和散射以及等离子体激元激发产生的倏逝近场组成。根据孔的孔径大小和形状，它在传播方向上呈现出振荡衰减。这种不寻常的场穿透是由这些贡献之间的干涉所解释的，并通过一个经过设计的孔径进行了实验验证，该孔径从一个简单的圆形伸出四条臂，以操纵金属膜中可用的特定等离子体激元激发。数值模拟定量地支持了该实验。这一基本特性将通过孔径工程设计近场，对用于实际应用的等离子体激元学产生影响。
