# Rigorous Analytical Model for Metasurface Microscopic Design with Interlayer Coupling

## TL;DR

This paper introduces a semianalytical model for designing multilayered metasurfaces that accurately accounts for interlayer coupling effects, providing a reliable alternative to full-wave optimization methods.

## Contribution

The authors develop a rigorous semianalytical model for multilayer metasurface design that explicitly includes near-field interlayer coupling effects, enhancing accuracy for small spacings.

## Key findings

- Model accurately predicts interlayer coupling effects
- Verification with commercial solvers confirms reliability
- Enables design of metasurfaces with very small interlayer spacings

## Abstract

We present a semianalytical method for designing meta-atoms in multilayered metasurfaces (MSs), relying on a rigorous model developed for multielement metagratings. Notably, this model properly accounts for near-field coupling effects, allowing reliable design even for extremely small interlayer spacings, verified via commercial solvers. This technique forms an appealing alternative to the common full-wave optimization employed for MS microscopic design to date.