High-subwavelength-resolution imaging of multilayered structures consisting of alternating negative-permittivty and dielectric layers with flattened transmission curves

TL;DR

This paper proposes a method to achieve high-resolution imaging of multilayered structures by merging transmission peaks to create flat transmission curves, improving evanescent wave transmission for subwavelength imaging.

Contribution

It introduces a novel approach to flatten transmission curves in multilayered negative-permittivity and dielectric structures, enhancing subwavelength imaging capabilities.

Findings

Merged transmission peaks lead to flat upheavals on curves.

Enhanced evanescent wave transmission over a broad range.

Elimination of sharp peaks improves imaging quality.

Abstract

Multilayered structures consisting of alternating negative-permittivity and dielectric layers are explored to obtain high-resolution imaging of subwavelength objects. The peaks with the smallest |ky| (ky is the transverse wave vector) on the transmission curves, which come from the guided modes of the multilayered structures, can not be completely damped by material loss. This makes the amplitudes of the evanescent waves around these peaks inappropriate after transmitted through the imaging structures, and the imaging quality is not good. To solve such a problem, the permittivity of the dielectric layers is appropriately chosen to make these sharp peaks merge with their neighboring peaks. Wide flat upheavals are then generated on the transmission curves so that evanescent waves in a large range are transmitted through the structures with appropriate amplitudes. In addition, it is found that the sharp peaks with the smallest |ky| can be eliminated by adding appropriate coating layers and wide flat upheavals can also be obtained.