scholarly journals Experimental Demonstration of Electromagnetically Induced Transparency in a Conductively Coupled Flexible Metamaterial with Cheap Aluminum Foil

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Jie Hu ◽  
Tingting Lang ◽  
Weihang Xu ◽  
Jianjun Liu ◽  
Zhi Hong
Keyword(s):  
Electromagnetically Induced Transparency ◽  
Near Field ◽  
Surface Current ◽  
Aluminum Foil ◽  
Ring Resonators ◽  
Dark Mode ◽  
Field Coupling ◽  
New Ideas ◽  
Induced Transparency ◽  
Bright Mode

AbstractWe propose a conductively coupled terahertz metallic metamaterial exhibiting analog of electromagnetically induced transparency (EIT), in which the bright and dark mode antennae interact via surface currents rather than near-field coupling. Aluminum foil, which is very cheap and often used in food package, is used to fabricate our metamaterials. Thus, our metamaterials are also flexible metamaterials. In our design, aluminum bar resonators and aluminum split ring resonators (SRRs) are connected (rather than separated) in the form of a fork-shaped structure. We conduct a numerical simulation and an experiment to analyze the mechanism of the proposed metamaterial. The surface current due to LSP resonance (bright mode) flows along different paths, and a potential difference is generated at the split gaps of the SRRs. Thus, an LC resonance (dark mode) is induced, and the bright mode is suppressed, resulting in EIT. The EIT-like phenomenon exhibited by the metamaterial is induced by surface conducting currents, which may provide new ideas for the design of EIT metamaterials. Moreover, the process of fabricating microstructures on flexible substrates can provide a reference for producing flexible microstructures in the future.

Ultra-Broadband Electromagnetically induced Transparency in Metamaterial Based on Conductive Coupling

2021 ◽  
Author(s):  
Tiantian Zheng ◽  
Zhongyin Xiao ◽  
Mingming Chen ◽  
Xiang Miao ◽  
Xiaoyu Wang
Keyword(s):  
Slow Light ◽  
Electromagnetically Induced Transparency ◽  
Type System ◽  
Surface Current ◽  
Wide Band ◽  
Light Filter ◽  
Ring Resonators ◽  
Linear Optics ◽  
Dark Mode ◽  
Induced Transparency

Abstract In this paper, a structure comprising a horizontal metal strip resonator(SR) and four C-shape ring resonators(CRRs) is proposed, obtaining a broadband electromagnetically induced transparency-like(EIT-like) effect. The SR and CRRs are classified into bright mode and dark mode depending on whether they can be directly excited by the incident electromagnetic wave. The three-level Λ -type system and electric field are used to explain the mechanism of EIT-like effect. Meanwhile, by decreasing the distance between SR and CRRs, a transparency window of 1.4THz with relative bandwidth of 91.93% is observed. It is found that when the bright and dark mode are directly contacted, the EIT window increases rapidly via conductive coupling, which can be explained by the surface current. Our work provides a new method for wide band EIT-like effect, which has certain value in the field of slow light, filter and non-linear optics.

scholarly journals Dynamically Tunable Resonant Strength in Electromagnetically Induced Transparency (EIT) Analogue by Hybrid Metal-Graphene Metamaterials

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 171 ◽  
Author(s):  
Chaode Lao ◽  
Yaoyao Liang ◽  
Xianjun Wang ◽  
Haihua Fan ◽  
Faqiang Wang ◽  
...  
Keyword(s):  
Optical Networks ◽  
Electromagnetically Induced Transparency ◽  
Near Field ◽  
Monolayer Graphene ◽  
Dark Mode ◽  
Resonance Strength ◽  
Field Coupling ◽  
Terahertz Communications ◽  
Unit Cells ◽  
Induced Transparency

In this paper, a novel method to realize a dynamically tunable analogue of EIT for the resonance strength rather than the resonance frequency is proposed in the terahertz spectrum. The introduced method is composed of a metal EIT-like structure, in which a distinct EIT phenomenon resulting from the near field coupling between bright and dark mode resonators can be obtained, as well as an integrated monolayer graphene ribbon under the dark mode resonator that can continuously adjust the resonance strength of transparency peak by changing the Fermi level of the graphene. Comparing structures that need to be modulated individually for each unit cell of the metamaterials, the proposed modulation mechanism was convenient for achieving synchronous operations for all unit cells. This work demonstrates a new platform of modulating the EIT analogue and paves the way to design terahertz functional devices which meet the needs of optical networks and terahertz communications.

scholarly journals Analog of multiple electromagnetically induced transparency using double-layered metasurfaces

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Siyuan Liu ◽  
Zhixia Xu ◽  
Xiaoxing Yin ◽  
Hongxin Zhao
Keyword(s):  
Electromagnetically Induced Transparency ◽  
Near Field ◽  
Localized Surface Plasmons ◽  
Dark Mode ◽  
Field Coupling ◽  
Double Peaks ◽  
Resonant Modes ◽  
Physical Essence ◽  
Induced Transparency ◽  
Mode A

Abstract We reported an analog of electromagnetically induced transparency (A-EIT) featured by double transparent peaks in the spectrum. The A-EIT is realized by double-layered metasurface which consists of spoof localized surface plasmons (S-LSP) and cut-wire (CW)-square rings (SR) hybrid. Electric and magnetic S-LSP are excited as bright and dark modes respectively then couple with resonant modes of CW and SR simultaneously to achieve multiple A-EIT. Two bright modes of the electric S-LSP and SR are excited by external electric field directly that produce a bright-bright mode A-EIT. Moreover, the magnetic S-LSP, which cannot be excited by external field directly, is excited through near field coupling from CW, inducing another bright-dark mode A-EIT. Theoretical analysis with corresponding experiment in microwave band are introduced for better insights into physical essence of the double-peaks A-EIT.

scholarly journals Independently tunable electromagnetically induced transparency effect and dispersion in a multi-band terahertz metamaterial

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rakesh Sarkar ◽  
Dipa Ghindani ◽  
Koijam Monika Devi ◽  
S. S. Prabhu ◽  
Amir Ahmad ◽  
...  
Keyword(s):  
Slow Light ◽  
Electromagnetically Induced Transparency ◽  
Near Field ◽  
The Other ◽  
Transmission Spectra ◽  
Field Coupling ◽  
Induced Transparency ◽  
Coupled Harmonic Oscillator ◽  
Bright Mode ◽  
Multi Band

AbstractIn this article, we experimentally and numerically investigate a planar terahertz metamaterial (MM) geometry capable of exhibiting independently tunable multi-band electromagnetically induced transparency effect (EIT). The MM structure exhibits multi-band EIT effect due to the strong near field coupling between the bright mode of the cut-wire (CW) and dark modes of pair of asymmetric double C resonators (DCRs). The configuration allows us to independently tune the transparency windows which is challenging task in multiband EIT effect. The independent modulation is achieved by displacing one DCR with respect to the CW, while keeping the other asymmetric DCR fixed. We further examine steep dispersive behavior of the transmission spectra within the transparency windows and analyze slow light properties. A coupled harmonic oscillator based theoretical model is employed to elucidate as well as understand the experimental and numerical observations. The study can be highly significant in the development of multi-band slow light devices, buffers and modulators.

scholarly journals Broadband Filter and Adjustable Extinction Ratio Modulator Based on Metal-Graphene Hybrid Metamaterials

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1359 ◽  
Author(s):  
Haoying Sun ◽  
Lin Zhao ◽  
Jinsong Dai ◽  
Yaoyao Liang ◽  
Jianping Guo ◽  
...  
Keyword(s):  
Electromagnetically Induced Transparency ◽  
Extinction Ratio ◽  
Optical Filters ◽  
Superior Performance ◽  
Dark Mode ◽  
Terahertz Communications ◽  
Transmission Window ◽  
Induced Transparency ◽  
Bright Mode ◽  
Mode Resonator

A novel multifunctional device based on a hybrid metal–graphene Electromagnetically induced transparency (EIT) metamaterial at the terahertz band is proposed. It is composed of a parallel cut wire pair (PCWP) that serves as a dark mode resonator, a vertical cut wire pair (VCWP) that serves as a bright mode resonator and a graphene ribbon that serves as a modulator. An ultra-broadband transmission window with 1.23 THz bandwidth can be obtained. The spectral extinction ratio can be tuned from 26% to 98% by changing the Fermi level of the graphene. Compared with previous work, our work has superior performance in the adjustable bandwidth of the transmission window without changing the structure of the dark and bright mode resonators, and has a high extinction ratio and dynamic adjustability. Besides, we present the specific application of the device in filters and optical modules. Therefore, we believe that such a metamaterial structure provides a new way to actively control EIT-like, which has promising applications in broadband optical filters and photoelectric intensity modulators in terahertz communications.

scholarly journals Asymmetric excitation of surface plasmons by dark mode coupling

2016 ◽  
Vol 2 (2) ◽  
pp. e1501142 ◽  
Author(s):  
Xueqian Zhang ◽  
Quan Xu ◽  
Quan Li ◽  
Yuehong Xu ◽  
Jianqiang Gu ◽  
...  
Keyword(s):  
Surface Plasmons ◽  
Mode Coupling ◽  
Electromagnetic Waves ◽  
Electromagnetically Induced Transparency ◽  
Near Field ◽  
Coupling Mechanism ◽  
Dark Mode ◽  
Resolution Imaging ◽  
Experimental Findings ◽  
Induced Transparency

Control over surface plasmons (SPs) is essential in a variety of cutting-edge applications, such as highly integrated photonic signal processing systems, deep-subwavelength lasing, high-resolution imaging, and ultrasensitive biomedical detection. Recently, asymmetric excitation of SPs has attracted enormous interest. In free space, the analog of electromagnetically induced transparency (EIT) in metamaterials has been widely investigated to uniquely manipulate the electromagnetic waves. In the near field, we show that the dark mode coupling mechanism of the classical EIT effect enables an exotic and straightforward excitation of SPs in a metasurface system. This leads to not only resonant excitation of asymmetric SPs but also controllable exotic SP focusing by the use of the Huygens-Fresnel principle. Our experimental findings manifest the potential of developing plasmonic metadevices with unique functionalities.

scholarly journals Electrical Manipulation of Electromagnetically Induced Transparency for Slow Light Purpose Based on Metal-Graphene Hybrid Metamaterial

2018 ◽  
Vol 8 (12) ◽  
pp. 2672 ◽  
Author(s):  
Chenxi Liu ◽  
Song Zha ◽  
Peiguo Liu ◽  
Cheng Yang ◽  
Qihui Zhou
Keyword(s):  
Slow Light ◽  
Electromagnetically Induced Transparency ◽  
Critical Index ◽  
Hybrid Structure ◽  
Strip Width ◽  
Ring Resonators ◽  
Dark Mode ◽  
Surface Distribution ◽  
Induced Transparency ◽  
Hybrid Metamaterial

A terahertz metamaterial is presented and numerically investigated to achieve tunable electromagnetically induced transparency (EIT) for slow light. The unit cell consists of cut-wire pairs and U-shaped ring resonators with graphene strips placed between the metal film and the SiO2/Si substrate. Through bright-dark mode coupling, the radiative resonance induced by the U-shaped ring is suppressed, and then the typical EIT effect is realized. The transparency window and the accompanied group delay can be electrically manipulated with different Fermi energy of the graphene. By analyzing the surface distribution, the underlying tuning mechanism of this hybrid metamaterial is investigated in detail. Moreover, the transparency peak decreases slightly with the increasing strip width of the graphene layer but completely vanishes as the strip width exceeds the length of the covered U-shaped ring. The influence of the critical index of graphene quality, i.e., carrier mobility on the EIT effect, is considered. The results of this study may provide valuable guidance in designing and analyzing tunable EIT structures based on a metal-graphene hybrid structure for slow light purposes.

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