Super-resolution without Evanescent Waves

TL;DR

This paper introduces a super-resolution imaging method that bypasses evanescent waves by using a specially designed optical mask to generate superoscillations, enabling sub-wavelength focus and imaging at a distance.

Contribution

The authors propose a novel super-resolution technique utilizing superoscillation masks, eliminating the need for evanescent fields and proximity to the object, which is a significant advancement over traditional methods.

Findings

Demonstrated sub-wavelength focusing using superoscillation masks

Achieved super-resolution imaging without evanescent waves

Validated the approach with theoretical and experimental results

Abstract

The last decade has seen numerous efforts to achieve imaging resolution beyond that of the Abbe-Rayleigh diffraction limit. The main direction of research aiming to break this limit seeks to exploit the evanescent components containing fine detail of the electromagnetic field distribution at the immediate proximity of the object. Here we propose a solution that removes the need for evanescent fields. The object being imaged or stimulated with sub-wavelength accuracy does not need to be in the immediate proximity of the superlens or field concentrator: an optical mask can be designed that creates constructive interference of waves known as superoscillation, leading to a sub-wavelength focus of prescribed size and shape in a `field of view' beyond the evanescent fields, when illuminated by a monochromatic wave. Moreover, we demonstrate that such a mask may be used not only as a focusing device, but also as a super-resolution imaging device.