Pseudocanalization regime for magnetic dark-field hyperlens

TL;DR

This paper introduces a novel magnetic hyperlens design that achieves pseudocanalization, enabling superresolution imaging of weak scatterers while maintaining dark-field filtering, thus overcoming limitations of traditional hyperlens configurations.

Contribution

The authors propose using magnetic hyperbolic metamaterials to realize pseudocanalization, enhancing tunability and preserving dark-field filtering in hyperlens imaging.

Findings

Pseudocanalization achieves image quality comparable to conventional hyperlenses.

Magnetic HMMs enable phase cancellation and improved light propagation control.

Dark-field filtering is maintained in the proposed hyperlens design.

Abstract

Hyperbolic metamaterials (HMMs) are the cornerstone of the hyperlens, which brings the superresolution effect from the near-field to the far-field zone. For effective application of the hyperlens it should operate in so-called canalization regime, when the phase advancement of the propagating fields is maximally supressed, and thus field broadening is minimized. For conventional hyperlenses it is relatively straightforward to achieve canalization by tuning the anisotropic permittivity tensor. However, for a dark-field hyperlens designed to image weak scatterers by filtering out background radiation (dark-field regime) this approach is not viable, because design requirements for such filtering and elimination of phase advancement i.e. canalization, are mutually exclusive. Here we propose the use of magnetic ($\mu$-positive and negative) HMMs to achieve phase cancellation at the output equivalent to the performance of a HMM in the canalized regime. The proposed structure offers additional flexibility over simple HMMs in tuning light propagation. We show that in this ``pseudocanalizing'' configuration quality of an image is comparable to a conventional hyperlens, while the desired filtering of the incident illumination associated with the dark-field hyperlens is preserved.