Liao Zixuan, Ma Qichang, Wang Longxiao, Yang Zhi, Li Meiqi, Deng Fu, Hong Weiyi
Opt Express. 2022 Jul 4;30(14):24676-24688. doi: 10.1364/OE.463340.
The electromagnetically induced transparency (EIT) effect realized in a metasurface is potential for slow light applications for its extreme dispersion variation in the transparency window. Herein, we propose an all-dielectric metasurface to generate a double resonance-trapped quasi bound states in the continuum (BICs) in the form of EIT or Fano resonance through selectively exciting the guiding modes with the grating. The group delay of the EIT is effectively improved up to 2113 ps attributing to the ultrahigh Q-factor resonance carried by the resonance-trapped quasi-BIC. The coupled harmonic oscillator model and a full multipole decomposition are utilized to analyze the physical mechanism of EIT-based quasi-BIC. In addition, the BIC based on Fano and EIT resonance can simultaneously exist at different wavelengths. These findings provide a new feasible platform for slow light devices in the near-infrared region.
超表面中实现的电磁诱导透明（EIT）效应因其在透明窗口内的极端色散变化而在慢光应用方面具有潜力。在此，我们提出一种全介质超表面，通过用光栅选择性地激发导模，以EIT或法诺共振的形式产生双共振捕获的连续域中的准束缚态（BICs）。由于共振捕获的准BIC所携带的超高品质因数共振，EIT的群延迟有效地提高到了2113皮秒。利用耦合谐波振荡器模型和全多极分解来分析基于EIT的准BIC的物理机制。此外，基于法诺共振和EIT共振的BIC可以在不同波长下同时存在。这些发现为近红外区域的慢光器件提供了一个新的可行平台。
