Magnified imaging based on non-Hermitian nonlocal cylindrical metasurfaces

TL;DR

This paper demonstrates how non-Hermitian nonlocal cylindrical metasurfaces can achieve magnified imaging with reduced aberrations, combining analytical derivations and numerical simulations to validate the concept.

Contribution

It introduces a novel cylindrical lensing system using non-Hermitian nonlocal metasurfaces for high-quality magnified imaging, extending previous planar designs.

Findings

Analytical surface-impedance values for perfect magnification

Proof-of-principle multilayered metasurface implementations

Stable frequency-dispersion laws for arbitrary excitations

Abstract

We show that a cylindrical lensing system composed of two metasurfaces with suitably tailored non-Hermitian (i.e., with distributed gain and loss) and nonlocal (i.e., spatially dispersive) properties can perform magnified imaging with reduced aberrations. More specifically, we analytically derive the idealized surface-impedance values that are required for "perfect" magnification and imaging, and elucidate the role and implications of non-Hermiticity and nonlocality in terms of spatial resolution and practical implementation. For a basic demonstration, we explore some proof-of-principle quasi-local and multilayered implementations, and independently validate the outcomes via full-wave numerical simulations. We also show that the metasurface frequency-dispersion laws can be chosen so as to ensure unconditional stability with respect to arbitrary temporal excitations. These results, which extend previous studies on planar configurations, may open intriguing venues in the design of metastructures for field imaging and processing.