Model Order Reduction of Large-Scale Metasurfaces Using a Hierarchical Dipole Approximation

Abstract

Advances in the field of metasurfaces require simulation of large-scale metasurfaces that extend over many light wavelengths. Adopting standard numerical methods leads to models featuring a large number of degrees of freedom, which are prohibitive to solve within a time window compatible with the design workflow. Therefore, this demands developing the techniques to replace large-scale computational models with simpler ones, still capable of capturing the essential features but imposing a fraction of the initial computational costs. In this work, we present a simulation approach in order to handle reduced order analyses of large-scale metasurfaces of arbitrary elements. We use the discrete dipole approximation in conjunction with the discrete complex image method and hierarchical matrix construction as a common theoretical framework for dipole approximation in the hierarchy of individual elements and the array scale. We extract the contributions of multipoles in the scattering spectra of the nanoantennas f...