Chung Taerin, Lim Yongjun, Lee Il-Min, Lee Seoung-Yeol, Choi Jinyoung, Roh Sookyoung, Kim Kyoung-Youm, Lee Byoungho
National Creative Research Center for Active Plasmonics Application Systems, Inter-University Semiconductor Research Center and School of Electrical Engineering, Seoul National University, Seoul 151-744, Korea.
Opt Express. 2011 Oct 10;19(21):20751-60. doi: 10.1364/OE.19.020751.
We propose a compact nano-metallic structure for enhancing and concentrating far-field transmission: a faced folded nano-rod (FFR) unit, composed of two folded metallic nano-rods placed facing each other in an aperture. By analyzing local charge, field, and current distributions in the FFR unit using three-dimensional finite difference time domain (FDTD) calculation results, we show that although charge and field configurations become somewhat different depending on the polarization states of the illumination, similar current flows are formed in the FFR unit, which entail similar far-field radiation patterns regardless of the polarization states, making the FFR unit a quasi-polarization-insensitive field concentrator. We demonstrate this functionality of the FFR unit experimentally using the holographic microscopy which provides us a three-dimensional map of the complex wavefronts of optical fields emanating from the FFR unit.
一种面折叠纳米棒（FFR）单元，它由两根在孔径中彼此相对放置的折叠金属纳米棒组成。通过使用三维时域有限差分（FDTD）计算结果分析FFR单元中的局部电荷、场和电流分布，我们表明，尽管电荷和场的配置会根据照明的偏振状态而有所不同，但在FFR单元中会形成相似的电流，这导致无论偏振状态如何都有相似的远场辐射模式，使FFR单元成为一种准偏振不敏感的场集中器。我们使用全息显微镜通过实验证明了FFR单元的这一功能，全息显微镜为我们提供了从FFR单元发出的光场复波前的三维图。
