High Quality-Factor Dual-Band Fano Resonances Induced by Bound States in The Continuum Using A Planar Nanohole Slab

Abstract

In photonics, it is essential to achieve high quality (Q)-factor resonances to enhance light-mater interactions for improving performances of optical devices. Herein, we demonstrate that high Q-factor dual-band Fano resonances can be achieved by using a planar nanohole slab (PNS) based on the excitation of bound states in the continuum (BICs). By shrinking or expanding the tetramerized holes of the superlattice of the PNS, symmetry-protected BICs can be excited and the locations of Fano resonances as well as their Q-factors can be flexibly tuned. Physical mechanisms for the dual-band Fano resonances can be interpreted as the resonant couplings between the electric-toroidal dipoles or the magnetic-toroidal dipoles based on the far-field multiple decompositions and the near-field distributions of the superlattice. The dual-band Fano resonances of the PNS possess polarization independent feature, they can be survived even the geometric parameters of the PNS are significantly altered, making them more suitable for potential applications.

Symmetry-Engineered Dual Plasmon-Induced Transparency via Triple Bright Modes in Graphene Metasurfaces

“…In Figure 5c, it can be seen that with the increase of P, the two transmission windows are slightly blueshifted followed by a slight redshift. In Figure 5d, it can be seen that the dual PIT phenomenon can be maintained almost the same except a slight redshift of the resonance location with the increase of t, which features the Fabry-Pérot cavity modes confined in the structure [39]. Besides the influence of structural parameters on the graphene metasurface, the carrier mobility μ of graphene, which corresponds to the intrinsic loss of graphene, also plays an important role in the transmission responses, and the carrier mobility can be controlled by utilizing chemical doping or electric field tuning [40,41].…”