Comment on 'Propagation and Negative Refraction,' IEEE Microwave Magazine, pp. 58-65, July/August 2012

TL;DR

This paper clarifies misconceptions about negative refraction in metamaterials, emphasizing that the phenomena are consistent with causality and supported by extensive evidence, aiming to correct recent misleading statements.

Contribution

It provides a clear explanation of negative refraction physics, addressing and correcting misconceptions in recent literature.

Findings

Negative refraction is consistent with causality.

Extensive analytical, numerical, and experimental evidence supports negative refraction.

Clarifies physical meaning behind negative index metamaterials.

Abstract

We discuss and clarify some misleading statements appeared in a recent article on negative refraction in metamaterials. In this comment, we straighten the physical meaning and underlying phenomena behind negative refraction and negative index metamaterials and show that these phenomena are perfectly consistent with causality. It is hoped that this comment draws the attention of authors, reviewers and readers to the large body of rigorous analytical, numerical, and experimental evidence in favor of negative refraction at a single interface, so as to avoid reviving settled debates which mislead, rather than educate, the physics and engineering communities.