Switchable Electromagnetically Induced Transparency with Toroidal Mode in a Graphene-Loaded All-Dielectric Metasurface

作者：Guanghou Sun, Sheng Peng, Xuejin Zhang, Yong‐yuan Zhu · 发表于：Nanomaterials · 年份：2020 · DOI：10.3390/nano10061064 · 被引用次数：52 · 研究领域：Metamaterials and Metasurfaces Applications、Plasmonic and Surface Plasmon Research、Quantum optics and atomic interactions

Active photonics based on graphene has attracted wide attention for developing tunable and compact optical devices with excellent performances. In this paper, the dynamic manipulation of electromagnetically induced transparency (EIT) with high quality factors (Q-factors) is realized in the optical telecommunication range via the graphene-loaded all-dielectric metasurface. The all-dielectric metasurface is composed of split Si nanocuboids, and high Q-factor EIT resonance stems from the destructive interference between the toroidal dipole resonance and the magnetic dipole resonance. As graphene is integrated on the all-dielectric metasurface, the modulation of the EIT window is realized by tuning the Fermi level of graphene, engendering an appreciable modulation depth of 88%. Moreover, the group velocity can be tuned from c/1120 to c/3390. Our proposed metasurface has the potential for optical filters, modulators, and switches.