Strong effect of surfaces on resolution limit of negative-index "superlens"

TL;DR

This paper demonstrates that the imaging resolution of negative index superlenses is highly sensitive to surface properties, with small deviations drastically reducing resolution and affecting the polariton spectrum.

Contribution

It reveals the critical impact of surface deviations on the resolution limit of negative index superlenses, highlighting the importance of surface properties in superlens performance.

Findings

Minor deviations in surface permittivity or permeability reduce resolution.

Surface deviations can create a gap in the polariton spectrum.

Stationary regimes may exist without losses due to spectral gaps.

Abstract

We show that subwavelength imaging by negative index materials (NIM), related to their "soft" electromagnetic response, is very (and non trivially) sensitive to the surface properties. A minute deviation of dielectric permittivity epsilon or magnetic permeability mu from the ideal values epsilon = mu = -1 in thin surface layer(s) results in drastic reduction of the resolution limit of a NIM slab. There may be a gap in the polariton spectrum and this would allow establishment of a stationary regime even without losses.