High quality-factor resonances in an asymmetric pixelated metasurface

Abstract

We propose a pixel-based metasurface design with asymmetry parameters with a large number of pixels used to construct the unit cell. Each square-shaped pixel has only two states, either metal or dielectric. Typically, the unit cell is designed to have a rotational symmetry. However, in this work, we introduce a set of additional parameters that can break the symmetry of the unit cell, closely associated with the physics of bound states in the continuum. These asymmetry parameters, defined by the scale of pixels in two dimensions, induce Fano resonances with high quality-factors in the transmission spectra and allow for the design of frequency-selective metasurfaces that are more specific to the general frequency-response characteristics.