Sub-diffraction-limit Observation Realized by Nonlinear Metamaterial Lens

TL;DR

This paper demonstrates experimentally that a nonlinear metamaterial lens can achieve sub-diffraction-limit imaging by measuring harmonic frequencies and reconstructing images, promising advances in high-resolution electromagnetic imaging.

Contribution

It introduces a novel nonlinear metamaterial lens capable of sub-diffraction imaging through harmonic frequency analysis and inverse Fourier transformation.

Findings

Sub-diffraction imaging achieved with nonlinear lens

Clear resolution in far-field measurements

Potential for improved sub-wavelength resolution

Abstract

In this paper, we show by experiment that by covering a thin flat nonlinear lens on the sources, the sub-diffraction-limit observation can be achieved by measuring either the near-field distribution or the far-field radiation of the sources at the harmonic frequencies and calculating the inverse Fourier transformation to obtain the sub-wavelength imaging. Especially, the sub-wavelength image calculated from measured far-field data demonstrates very clear resolution. Since metamaterials included with active elements can easily behave strong nonlinearity under very weak incident electromagnetic powers, the application of the nonlinear lens proposed in this paper would have important potential in improving the sub-wavelength resolution in the near future.