Zhao Xueqian, Huang Rixing, Du Xiang, Zhang Zhenrong, Li Guangyuan
CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
School of Computer, Electronic and Information, Guangxi University, Nanning 530004, China.
Nano Lett. 2024 Jan 31;24(4):1238-1245. doi: 10.1021/acs.nanolett.3c04174. Epub 2024 Jan 5.
The metasurface analogue of electromagnetically induced transparency (EIT) provides a chip-scale platform for achieving light delay and storage, high factors, and greatly enhanced optical fields. However, the literature relies on the coupling between localized and localized or localized and collective resonances, limiting the factor and related performance. Here, we report a novel approach for realizing collective EIT-like bands with a measured factor reaching 2750 in silicon metasurfaces in the near-infrared regime, exceeding the state of the art by more than 5 times. It employs the coupling between two collective resonances, the Mie electric dipole surface lattice resonance (SLR) and the out-of-plane/in-plane electric quadrupole SLR (EQ-SLR). Remarkably, the collective EIT-like resonance can have diverging factor and group delay due to the bound state in the continuum characteristics of the in-plane EQ-SLR. With these findings, our study opens a new route for tailoring light flow in metasurfaces.
电磁诱导透明（EIT）的超表面类似物为实现光延迟与存储、高品质因数以及大幅增强的光场提供了一个芯片级平台。然而，现有文献依赖于局域与局域或局域与集体共振之间的耦合，限制了品质因数及相关性能。在此，我们报道一种在近红外波段的硅超表面中实现类集体EIT能带的新方法，其测得的品质因数达到2750，比现有技术水平高出5倍多。它利用了两种集体共振之间的耦合，即米氏电偶极表面晶格共振（SLR）和面外/面内电四极SLR（EQ-SLR）。值得注意的是，由于面内EQ-SLR的连续态束缚态特性，类集体EIT共振可以具有发散的品质因数和群延迟。基于这些发现，我们的研究为在超表面中调控光流开辟了一条新途径。
