Realization of broadband negative refraction in visible range using vertically stacked hyperbolic metamaterials.

Sanghun Bang,Sunae So,Junsuk Rho

doi:10.1038/s41598-019-50434-3

Sanghun Bang, Sunae So + Show 1 more

Open Access

https://doi.org/10.1038/s41598-019-50434-3

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Journal: Scientific Reports	Publication Date: Oct 1, 2019
Citations: 39	License type: open-access

Affiliation: Pohang University of Science and Technology

Abstract

Negative refraction has generated much interest recently with its unprecedented optical phenomenon. However, a broadband negative refraction has been challenging because they mainly involve optical resonances. This paper reports the realization of broadband negative refraction in the visible spectrum by using vertically-stacked metal-dielectric multilayer structures. Such structure exploits the characteristics of the constituent metal and dielectric materials, and does not require resonance to achieve negative refraction. Broadband negative refraction (wavelength 270–1300 nm) is numerically demonstrated. Compared to conventional horizontally-stacked multilayer structures, the vertically-stacked multilayer structure has a broader range of working wavelength in the visible range, with higher transmittance. We also report a variety of material combinations with broad working wavelength. The broadband negative refraction metamaterial provides an effective way to manipulate light and may have applications in super-resolution imaging, and invisibility cloaks.

Highlights

Metamaterials composed of nanostructures of artificial atoms have shown many extraordinary properties that cannot be found in natural materials[1,2]
The negative ε is obtained by conducting wires below the plasma frequency ωP, and negative μ occurs near the resonance frequency ωSRR of split-ring resonators (SRRs)
We suggest various vertical Hyperbolic metamaterials (HMMs) composed of different metal and dielectric materials

Summary

Introduction

Metamaterials composed of nanostructures of artificial atoms have shown many extraordinary properties that cannot be found in natural materials[1,2]. Www.nature.com/scientificreports constituents with sub-wavelength dimensions, so negative refraction under TM polarized light can be achieved in HMMs by manipulating ε even if they do not have negative n. In this paper, we present vertically-stacked metal-dielectric multilayer structures (vertical HMMs) to achieve broadband negative refraction.

Results

Conclusion