Vanadium Dioxide-Based Bifunctional Metamaterial for Terahertz Waves

Man Zhang,Apeng Chen,Zhengyong Song,Jiahe Zhang

doi:10.1109/jphot.2019.2958340

Abstract

A vanadium dioxide-based multilayer metamaterial is proposed with bifunctional properties of absorption and polarization conversion. When vanadium dioxide is in the metallic state, the designed system behaves as a single-band absorber which is composed of a vanadium dioxide disk-shaped array, a silica spacer, and a vanadium dioxide continuous film. The performance of absorption can be tuned by changing either the diameter of disk or the thickness of silica. The design of this absorber is robust against incident polarization and incident angle. The proposed single-band absorber may be generally applied for plasmonic detection, cavity resonator, and optical band-stop filter. When vanadium dioxide is in the insulating state, the designed system behaves as a cross polarization converter which mainly consists of a one-dimensional metallic strip-shaped array, a silica spacer, and a metallic continuous film. The designed metamaterial can convert a linear plane wave into its corresponding cross-polarized wave with the efficiency of >90% in the frequency of 2.0-3.0 THz. The physical mechanism of polarization conversion is explained by a simple picture. The proposed metamaterial could be a potential candidate for the modern device of polarization control.

Highlights

In the past decade, metamaterials, artificially manufactured materials arranged in periodic arrays, have attracted considerable research interest of researchers in the fields of electromagnetics and optics
When vanadium dioxide is in the insulating state, the designed system behaves as a cross polarization converter which mainly consists of a one-dimensional metallic strip-shaped array, a silica spacer, and a metallic continuous film
When VO2 is in the insulating state, the designed configuration behaves as an efficient cross polarization converter working in the reflective mode at terahertz frequencies

Summary

Introduction

Metamaterials, artificially manufactured materials arranged in periodic arrays, have attracted considerable research interest of researchers in the fields of electromagnetics and optics. This is because their unique electromagnetic properties and phenomena in many areas cannot be realized in natural materials, including negative refractive index [1]–[3], perfect lens [4]–[6], and polarization converter [7]–[9]. By designing artificial “meta-atoms”, the subwavelength structure of metamaterial can be flexibly tuned because it is determined by structures of the internal design rather than the chemical composition This characteristic enables metamaterial to have designable effective permittivity and permeability. With the development of metamaterial technology, in order to achieve active tunability and/or reconfigurability, metamaterial can be combined with graphene [16]–[18], phase change material [19]–[23], liquid crystal [24], ferrite [25], diode [26], and structure change [27]

Methods

Results

Conclusion