On metallic gratings coated conformally with isotropic negative-phase-velocity materials

TL;DR

This paper demonstrates that coating metallic gratings with negative-index materials can significantly improve non-specular reflection efficiencies compared to positive-index coatings, using the differential (C) method.

Contribution

It introduces the application of the differential method to analyze diffraction by metallic gratings coated with negative-phase-velocity materials, revealing enhanced reflection properties.

Findings

Negative-index coatings increase nonspecular reflection efficiency.

The differential method effectively models coated metallic gratings.

Negative materials outperform positive ones in specific diffraction scenarios.

Abstract

Application of the differential method (also called the C method) to plane-wave diffraction by a perfectly conducting, sinusoidally corrugated metallic grating coated with a linear, homogeneous, isotropic, lossless dielectric-magnetic material shows that coating materials with negative index of refraction may deliver enhanced maximum nonspecular reflection efficiencies in comparison to coating materials with positive index of refraction.