Imaging the Near Field

TL;DR

This paper refines the perfect lens concept by proposing a multi-layer stack of positive and negative refractive media that enhances near-field imaging resolution and reduces absorption effects.

Contribution

It introduces a multi-layer design that is less sensitive to imperfections and acts like a near-field fibre-optic bundle, improving near-field imaging.

Findings

Multi-layer stacks reduce sensitivity to material imperfections.

Thinner layers minimize retardation effects.

Absorption limits near-field resolution, but thinner layers mitigate this.

Abstract

In an earlier paper we introduced the concept of the perfect lens which focuses both near and far electromagnetic fields, hence attaining perfect resolution. Here we consider refinements of the original prescription designed to overcome the limitations of imperfect materials. In particular we show that a multi-layer stack of positive and negative refractive media is less sensitive to imperfections. It has the novel property of behaving like a fibre-optic bundle but one that acts on the near field, not just the radiative component. The effects of retardation are included and minimized by making the slabs thinner. Absorption then dominates image resolution in the near-field. The deleterious effects of absorption in the metal are reduced for thinner layers.