Multiscale analysis of subwavelength imaging with metal-dielectric multilayers

TL;DR

This paper investigates the complex, scale-dependent behavior of subwavelength imaging using metal-dielectric multilayers, revealing that traditional measures like PSF width are insufficient to assess resolution.

Contribution

It introduces a multiscale analysis approach to better understand the resolution limits and imaging properties of layered superlenses at subwavelength scales.

Findings

PSF width is not a reliable resolution measure

Subwavelength objects can be imaged smaller than PSF FWHM

Multiscale analysis reveals scale-dependent imaging properties

Abstract

Imaging with a layered superlens is a spatial filtering operation characterized by the point spread function (PSF). We show that in the same optical system the image of a narrow sub-wavelength Gaussian incident field may be surprisingly dissimilar to the PSF, and the width of PSF is not a straightforward measure of resolution. FWHM or std. dev. of PSF give ambiguous information about the actual resolution, and imaging of objects smaller than the FWHM of PSF is possible. A multiscale analysis of imaging gives good insight into the peculiar scale-dependent properties of sub-wavelength imaging.