Tailoring metallodielectric structures for superresolution and superguiding applications in the visible and near-ir ranges

Abstract

We discuss propagation effects in realistic, transparent, metallodielectric photonic band gap structures in the context of negative refraction and super-resolution in the visible and near infrared ranges. In the resonance tunneling regime, we find that for transverse-magnetic incident polarization, field localization effects contribute to a waveguiding phenomenon that makes it possible for the light to remain confined within a small fraction of a wavelength, without any transverse boundaries, due to the suppression of diffraction. This effect is related to negative refraction of the Poynting vector inside each metal layer, balanced by normal refraction inside the adjacent dielectric layer: The degree of field localization and material dispersion together determine the total momentum that resides within any given layer, and thus the direction of energy flow. We find that the transport of evanescent wave vectors is mediated by the excitation of quasistationary, low group velocity surface waves responsible for relatively large losses. As representative examples we consider transparent metallodielectric stacks such as Ag/TiO2 and Ag/ GaP and show in detail how to obtain the optimum conditions for high transmittance of both propagating and evanescent modes for super-guiding and super-resolution applications across the visible and near IR ranges. Finally, we study the influence of gain on super-resolution. We find that the introduction of gain can compensate the losses caused by the excitation of surface plasmons, improves the resolving characteristics of the lens, and leads to gain-tunable super-resolution

Spectral Domain Analysis of a Circular Nano-Aperture Illuminating a Planar Layered Sample

“…Our formulation is exact and it utilizes a transmission line analogue of the medium, which facilitates an efficient treatment of multilayered samples. The proposed method is applicable to experiments in SNOM when flat samples are evaluated, as well as in studies of metamaterial and metallodielectric multilayers for superlensing and superguidance applications at optical frequencies [19,20].…”

Flat lensing by periodic loss-modulated materials

“…Therefore, 2D GLMMs also allow beam shaping effects that can be used, among other functions, for spatial filtering purposes, as has been demonstrated for loss-modulated materials (LMMs) [14] and broad-area semiconductor amplifiers [15,16]. Also 1D gainloss layered structures have been considered for imaging purposes [17][18][19][20] or in the context of parity-time symmetry [21].…”

Impedance-Mismatched Hyperlens With Increasing Layer Thicknesses

“…As a result, the diffraction limit of conventional optics can be beaten by such a structure. Although the hyperlens which is composed of a (half) cylinder metamaterials is different from the multilayered structures, the imaging mechanism and parameters setting (e.g., permittivities) for subwavelength focusing (especially for multilayered system) in the previous research [9][10][11][12][13] will provide a lot of prospective and help for our current research in hyperlens. Moreover, systematical research on the cylindrical structure [14,15] and novel design approaches on the hyperlens (mainly on the impedance matched cases) [16][17][18] will also provide a lot of help and guidance.…”