Electromagnetic Surface Modes at Interfaces with Negative Refractive Index make a "Not-Quite-Perfect" Lens

TL;DR

This paper analyzes electromagnetic surface modes at interfaces with negative refractive index and shows that the concept of perfect imaging by negative-index slabs is limited by a large-wavenumber cutoff affecting resolution.

Contribution

It reveals that the perfect imaging theory requires a wavenumber cutoff, challenging the notion of perfect lenses made from negative-refractive-index materials.

Findings

Surface polariton modes support high wavenumbers at negative index interfaces

The perfect image formation is incomplete without considering a wavenumber cutoff

The resolution of negative-index lenses is limited by material-dependent wavenumber constraints

Abstract

Interfaces between media with negative relative refractive index generically support propagating electromagnetic surface polariton modes with large wavenumber. The relation of these modes to a recent prediction by Pendry of ``perfect (real) image formation'' by a parallel slab of negative-refractive-index material is analyzed. The ``perfect image'' theory is found to be incomplete without inclusion of a large-wavenumber cutoff that derives from a necessary wavenumber-dependence of the constitutive relations, and which controls the resolution of the image.