Quadrupolar susceptibility modeling of substrated metasurfaces with application to the generalized Brewster effect

TL;DR

This paper develops a comprehensive modeling framework for substrate-based metasurfaces incorporating quadrupolar responses, enabling advanced control of wave reflection and transmission phenomena such as the generalized Brewster effect.

Contribution

It introduces generalized sheet transition conditions including quadrupoles for metasurfaces on substrates, expanding the modeling capabilities for wave manipulation.

Findings

Demonstrates multiple angles of suppressed reflection (generalized Brewster effect)

Shows transmission suppression at specific angles (anti-Brewster effect)

Validates the model for practical, non-homogeneous metasurfaces

Abstract

We derive generalized sheet transition conditions (GSTCs) including dipoles and quadrupoles, using generalized functions (distributions). This derivation verifies that the GSTCs are valid for metasurfaces in non-homogeneous environments, such as for practical metasurfaces fabricated on a substrate. The inclusion of quadrupoles and modeling of spatial dispersion provides additional hyper-susceptibility components which serve as degrees of freedom for wave transformations. We leverage them to demonstrate a generalized Brewster effect with multiple angles of incidence at which reflection is suppressed, along with an ``anti-Brewster'' effect where transmission is suppressed.