Tunable and switchable multi-functional terahertz metamaterials based on a hybrid vanadium dioxide–graphene integrated configuration

Abstract

In this paper, an actively tunable and switchable multi-functional terahertz metamaterial device based on hybrid vanadium dioxide (VO2)-graphene-integrated configuration is proposed. By transiting the phase of VO2, the functions of...

An active tunable terahertz functional metamaterial based on hybrid-graphene vanadium dioxide

“…In simulations, periodic boundary conditions were applied in both the x and y directions, and the perfectly matched layers were used to absorb the light coming out of the boundaries in the z -direction. In the THz region, SiO 2 can be seen as a transparent material with a refractive index of 1.96, and we adopted the Drude model to describe the effective permittivity of Au and VO 2 : 34,35 where ω p = 1.37 × 10 16 Hz is the plasma frequency of Au, and the collision frequency γ Au = 4.08 × 10 13 Hz. ε ∞ = 12 is the permittivity of VO 2 at the high frequency limit, and the collision frequency γ VO 2 is set as 5.75 × 10 13 rad m −1 , 36 and ω p ( σ ) is the plasma frequency relying on the conductivity σ :where σ 0 = 3 × 10 5 S m −1 , and ω p ( σ 0 ) = 1.4 × 10 15 rad m −1 .…”

“…33 Very recently, Tang et al combined graphene and VO 2 to demonstrate a metamaterial device with tunable asymmetric transmission and polarization conversion. 34 Nevertheless, to our knowledge, the operating frequency ranges of the current functional metamaterial devices are still limited, and few works have been reported on the realization of switching between the strong CD and dual-band perfect absorption.…”

A high-performance terahertz absorber based on synthetic-patterned vanadium dioxide metamaterials

“…In recent years, researchers have combined phase change materials such as graphene, [29][30][31][32] liquid crystals, 33,34 bulk Dirac semimetals [35][36][37] and VO 2 [38][39][40][41] with metamaterial absorbers to achieve the tunable properties of absorbers. VO 2 is a commonly used phase change material.…”

Reconfigurable broadband metasurfaces with nearly perfect absorption and high efficiency polarization conversion in THz range

“…Generally, conventional metasurfaces have been usually designed for a single functionality. Recently, reconfigurable metasurfaces (RMSs) have been proposed that exhibit diversified functionalities together into one single device including bi-functionalities of linear polarization conversion (LPC) and circular polarization conversion (CPC) 15 – 20 , absorption (ABS) and reflection 5 , 21 – 24 , ABS and polarization conversion (PC) 25 – 38 . To achieve reconfigurable multifunctional metasurfaces, some approaches have been proposed such as mechanical shape-changing 31 , 39 and integrating with lumped elements 5 , 28 – 30 , 40 .…”

“…Therefore, metasurfaces that facilitate the effective integration of multiple functionalities into one structure have become an emerging research area, especially interesting for the terahertz (THz) range 41 . More recently, the incorporation of standard metasurfaces with phase-change materials (PCMs), such as Chalcogenide GeSbTe(GST) alloys 42 , Vanadium dioxide (VO ) 23 , 33 – 38 and graphene 18 , 20 , 26 , 27 , 43 have been proposed to realize the multifunctional metasurfaces. However, compared with PCM materials, graphene based method is still required high cost and sophistication for the manufacturing process.…”