Toroidal dipole Fano resonances supported by lattice-perturbed dielectric nanohole arrays in the near-infrared region

摘要

The toroidal dipole (TD) plays an important role in light-matter interactions. In this paper, a lattice-perturbed dielectric nanohole array structure has been put forward to excite dominant TD Fano resonances in the nearinfrared region. Herein, the numerical investigations and experimental demonstrations have been performed to characterize the TD Fano resonances with a series of lattice perturbations. The scattering power of TD and quality (Q)-factor of the resonance can be tailored by tuning perturbation. By using the lattice perturbation of 53 nm, the highest experimental Q-factor of 584 is obtained. (C) 2021 Optical Society of America