Ultimate resolution of indefinite metamaterial flat lenses

TL;DR

This paper demonstrates that indefinite metamaterials with hyperbolic dispersion can be characterized by a complex effective index, enabling systematic optimization of flat lenses that achieve super-resolution even with absorption, surpassing previous designs.

Contribution

It introduces a method to characterize indefinite metamaterials with a complex effective index, facilitating optimized flat lens designs with super-resolution capabilities.

Findings

Achieves super-resolved images up to one wavelength from the lens edge.

Outperforms state-of-the-art flat lenses in resolution.

Effective index characterization enables systematic lens optimization.

Abstract

We show that any metallo-dielectric multilayer with a hyperbolic dispersion relation can actually be characterized by a complex effective index. This refractive index, extracted from the complex Bloch band diagram, can be directly linked to the super-resolution of a flat lens made of this so- called indefinite metamaterials. This allows for a systematic optimization of the lens design, leading to structures that are outperforming state-of-art flat lenses. We show that, even when fully taking absorption into account, our design provides super-resolved images for visible light up to a distance of one wavelength from the lens edge.