基于平面超材料的Fano谐振可调谐研究

基于两段相同金属分裂环谐振器构成的单层结构, 从理论及实验方面研究了平面超材料的可调谐Fano谐振. 实验测量了平面超材料对TE和TM入射波的电磁响应, 利用电磁波的入射角度控制Fano谐振的强度, 实现了谐振的开关特性, 谐振频率红移可达到21%. 基于有限元法给出了平面超材料的场分布, 强的正常色散表明平面超材料的电磁响应可类比经典电磁诱导透明现象, 仿真与实验结果相符合. 对称结构超材料Fano谐振的开/关特性为超材料性能的可调谐控制提供了有效途径.

Tuning Fano resonances in a planar metamaterial

We demonstrate the tuning of Fano resonances in a symmetric planar metamaterial both experimentally and theoretically, on the basis of a unit cell consisting of two identical split ring resonators. The electromagnetic responses of the planar metamaterial to incident TE and TM waves are measured. By controlling the excitation of the Fano-type trapped-mode resonance via the angle of incidence, the resonance can be switched on/off and the resonance is red-shifted by up to 21%. Based on the finite element method, the field distributions are presented and a very sharp normal phase dispersion renders the response of the structure a metamaterial analog of classical electromagnetically-induced transparency (EIT). The simulated results are in good agreement with the measured ones. The switching feature of the trapped mode resonance in symmetric metamaterial can provide an easy approach to tuning the performance of metamaterial.