School of Electrical and Computer Engineering, Oklahoma State University, Stillwater, Oklahoma 74078, USA.
Opt Lett. 2011 Aug 1;36(15):2901-3. doi: 10.1364/OL.36.002901.
Arrays of subwavelength dipole bow-tie apertures are designed and characterized at terahertz frequencies. For an incident terahertz field perpendicular to the longer axis of the bow tie, a strong resonance enhancement, line narrowing, and a nonmonotonic frequency shift were observed with increasing length of the tapered bow-tie arms. Such characteristic behaviors primarily originate from localized surface plasmon resonances. In addition, with a decreasing aperture size, the contribution of localized plasmons becomes prominent due to an increase in plasmonic lifetime as the terahertz pulses strongly couple with the metallic surface surrounding the bow-tie apertures.
亚波长偶极子蝴蝶结阵列在太赫兹频率下进行了设计和特性研究。对于垂直于蝴蝶结较长轴的太赫兹入射场，随着锥形蝴蝶结臂长度的增加，观察到强烈的共振增强、线宽变窄和非单调频率位移。这种特征行为主要源于局域表面等离激元共振。此外，随着孔径尺寸的减小，由于太赫兹脉冲与蝴蝶结孔周围的金属表面强烈耦合，等离子体的寿命增加，局域等离子体的贡献变得更加显著。
