Broadband negative refraction in stacked fishnet metamaterial

TL;DR

This paper presents a theoretical and numerical study of a stacked fishnet metamaterial that achieves broadband negative refraction and subwavelength imaging across a wide frequency range, including zero frequency.

Contribution

It introduces a novel scheme utilizing negative evanescent coupling in stacked fishnet structures for all-angle negative refraction and imaging, verified by FDTD simulations.

Findings

Demonstrates negative refraction from zero frequency upwards

Validates theoretical predictions with FDTD simulations

Shows potential for wideband subwavelength imaging

Abstract

We demonstrate a scheme to utilize the stacked fishnet metamaterial for all-angle negative refraction and subwavelength imaging within a wide frequency range starting from zero frequency. The theoretical predictions are verified by the finite-difference-in-time-domain (FDTD) numerical simulations. The phenomena come from the negative evanescent coupling between the adjacent slab waveguides through the breathing air holes perforated on metal layers.