A Review: The Functional Materials-Assisted Terahertz Metamaterial Absorbers and Polarization Converters

Abstract

When metamaterial structures meet functional materials, what will happen? The recent rise of the combination of metamaterial structures and functional materials opens new opportunities for dynamic manipulation of terahertz wave. The optical responses of functional materials are greatly improved based on the highly-localized structures in metamaterials, and the properties of metamaterials can in turn be manipulated in a wide dynamic range based on the external stimulation. In the topical review, we summarize the recent progress of the functional materials-based metamaterial structures for flexible control of the terahertz absorption and polarization conversion. The reviewed devices include but are not limited to terahertz metamaterial absorbers with different characteristics, polarization converters, wave plates, and so on. We review the dynamical tunable metamaterial structures based on the combination with functional materials such as graphene, vanadium dioxide (VO2) and Dirac semimetal (DSM) under various external stimulation. The faced challenges and future prospects of the related researches will also be discussed in the end.

Designing a High-Sensitivity Microscale Triple-Band Biosensor Based on Terahertz MTMs to Provide a Perfect Absorber for Non-Melanoma Skin Cancer Diagnostic

“…For bulk materials, properties hinge on the effects of permittivity (ε) and permeability (μ), characterizing the polarizing capability of the material under the influence of electric and magnetic fields, respectively [17]. Metamaterials have introduced innovative avenues for controlling electromagnetic waves, yielding remarkable optical phenomena like superlensing, electromagnetically-induced transparency, perfect absorption, and polarization conversion [18]. As specific subtypes, metamaterials can be manipulated to construct absorbers and polarization converters in the terahertz frequency region, achieving near unity absorption and polarization conversion across a small or broad frequency range.…”

All-Silicon Polarization-Insensitive Metamaterial Absorber in the Terahertz Range

“…These MAs can be called single-band or multi-band MAs. Broadband THz MAs have attracted intense attention and a great deal of interest because of their urgent needs in THz shielding, imaging, polarization conversion, and related fields [19][20][21][22][23]. Once the structure of the metamaterial absorber is determined, the absorption situation is difficult to change.…”

A tunable broadband terahertz MoS2 absorber using series–parallel hybrid network design

“…In recent years, with the discovery of twodimensional (2D) materials, 9 they have been widely used in metamaterial absorbers. [10][11][12] 2D materials, such as graphene, MoS 2 , and black phosphorus, have ultra-high specific surface areas, making their electromagnetic properties susceptible to voltage biasing. 13,14 Therefore, 2D material absorbers can be used to change the surface conductivity by applying an external voltage, and to provide the tunable absorption properties.…”