Diffractive Interface Theory: Nonlocal polarizability approach to the optics of metasurfaces

TL;DR

This paper introduces Diffractive Interface Theory (DIT), a new formalism for analyzing the optics of metasurfaces that simplifies calculations by leveraging their thinness and directly relates their structure to diffraction properties.

Contribution

The paper presents DIT, a novel approach that bypasses complex internal light propagation calculations, enabling efficient and accurate analysis of metasurface diffraction and light-matter interactions.

Findings

DIT accurately predicts diffraction patterns of metasurfaces.

Validation against full-wave simulations confirms DIT's accuracy.

DIT offers computational advantages for designing and optimizing metasurfaces.

Abstract

We present a formalism for understanding the elecromagnetism of metasurfaces, optically thin composite films with engineered diffraction. The technique, diffractive interface theory (DIT), takes explicit advantage of the small optical thickness of a metasurface, eliminating the need for solving for light propagation inside the film and providing a direct link between the spatial profile of a metasurface and its diffractive properties. Predictions of DIT are compared with full-wave numerical solutions of Maxwell's equations, demonstrating DIT's validity and computational advantages for optically thin structures. Applications of the DIT range from understanding of fundamentals of light-matter interaction in metasurfaces to efficient analysis of generalized refraction to metasurface optimization.