对称平面特异材料中的类Fano谐振(英文)

Fano-like Resonances in Symmetric Planar Metamaterials

从理论和实验上研究了一种具有C3对称性的平面特异材料中的类Fano谐振模式。该平面特异材料由互补劈裂开口环谐振器(CSRRs)周期排列而成,每个原胞包含3个缝隙,具有三度旋转对称性。当水平偏振的电磁波入射到该结构时,具有高品质因子的类Fano谐振模式可以被激励,透过率频谱上表现为尖锐的谐振峰。该类Fano谐振由单元内3个CSRR局域模式的平面内耦合形成的对称态和反对称态耦合产生,在传感器、滤波器方面有广阔的应用前景。

The Fano-like resonance in symmetric planar metamaterials comprised of complimentary split ring resonators（CSRRs） is investigated by calculations from modal expansion method and transmission measurements.The Fano-like resonance is observed for one polarization with electric field component parallel to the mirror line of the structure,while only the broad dipole response can be found for the cross-polarization.Numerical simulations of field distributions reveal that the sharp response arises from the excitation of subradiant mode with nearly zero net dipole moment and poorly coupled with free space photons.The fast roll-off characteristic of Fano-like resonances is favorable for filtering and sensing applications.