Transmission function properties for multi-layered structures: Application to super-resolution

TL;DR

This paper analyzes the transmission function in multi-layered structures, revealing how evanescent mode amplification and phase slope relate to super-resolution capabilities, supported by analytical demonstrations and practical examples.

Contribution

It provides analytical insights into the transmission properties of multi-layered structures, linking evanescent amplification and phase behavior to super-resolution.

Findings

Evanescent modes can be amplified when guided modes are supported.

The phase slope of the transmission function inversely relates to diffraction compensation.

Super-resolution is achieved through evanescent amplification and diffraction correction.

Abstract

We discuss the properties of the transmission function in the k-space for a generic multi-layered structure. In particular we analytically demonstrate that a transmission greater than one in the evanescent spectrum (amplification of the evanescent modes) can be directly linked to the guided modes supported by the structure. Moreover we show that the slope of the phase of the transmission function in the propagating spectrum is inversely proportional to the ability of the structure to compensate the diffraction of the propagating modes. We apply these findings to discuss several examples where super-resolution is achieved thanks to the simultaneous availability of the amplification of the evanescent modes and the diffraction compensation of the propagating modes.