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

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 near-infrared 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.