Zhang Zhong Xiang, Chan Kam Tai
Department of Electronic Engineering, The Chinese University of Hong Kong, Hong Kong.
Opt Express. 2011 Jan 31;19(3):2791-6. doi: 10.1364/OE.19.002791.
Dual-layer metallic wire-hole structures were fabricated and their terahertz transmission properties were measured. They exhibit polarization-dependent transmittance with large extinction ratios. Simulation and experimental results on structures with different wire-to-hole orientations provide strong evidence that the resonance peaks are caused by plasmonic coupling between the two metallic layers. A simplified LC-circuit model is proposed to explain the coupling mechanism and to estimate the peak frequencies. Our results suggest that specific electromagnetic response can be achieved by appropriate design of the geometrical patterns on the two metallic layers and a suitable polarization of the incident wave.
制备了双层金属线孔结构，并测量了它们的太赫兹传输特性。它们表现出具有大消光比的偏振依赖透射率。对具有不同线与孔取向的结构的模拟和实验结果提供了有力证据，证明共振峰是由两个金属层之间的等离子体耦合引起的。提出了一个简化的LC电路模型来解释耦合机制并估计峰值频率。我们的结果表明，通过适当设计两个金属层上的几何图案以及入射波的合适偏振，可以实现特定的电磁响应。
