Possibility of anapole state in dielectric nanohole array metasurfaces with different hole shapes

TL;DR

This paper demonstrates that dielectric nanohole array metasurfaces with various hole shapes can support optical anapole states, enabling strong field confinement and suppressed scattering, useful for advanced nanophotonic applications.

Contribution

It introduces the design of high-index dielectric nanohole metasurfaces with different hole profiles that can support anapole states, supported by multipole analysis and simulations.

Findings

Nanohole array metasurfaces can support anapole states

Different hole shapes influence the anapole resonance

High-index metasurfaces with anapole states are feasible

Abstract

The optical anapole resonances in nanostructures display strong field confinement and substantially suppressed scattering. In this study using three-dimensional finite-difference time-domain simulations, it is shown that high refractive index dielectric nanohole array metasurfaces having different profiles of the holes can possess the anapole state. The multipole decomposition including the dipole electric toroidal moment for the lattice elements of the arrays is provided. The anapole state in the lattice elements is illustrated by time-averaged distributions of the energy. As a result, high-index freestanding metasurfaces with anapole state can be designed.