scholarly journals Numerical and Theoretical Study of Tunable Plasmonically Induced Transparency Effect Based on Bright–Dark Mode Coupling in Graphene Metasurface

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 232 ◽  
Author(s):  
Qichang Ma ◽  
Jianan Dai ◽  
Aiping Luo ◽  
Weiyi Hong
Keyword(s):  
Slow Light ◽  
Theoretical Calculations ◽  
Complex Surface ◽  
Infrared Region ◽  
Ring Resonators ◽  
Geometrical Parameters ◽  
Dark Mode ◽  
Graphene Layers ◽  
Induced Transparency ◽  
Plasmonically Induced Transparency

In this paper, we numerically and theoretically study the tunable plasmonically induced transparency (PIT) effect based on the graphene metasurface structure consisting of a graphene cut wire (CW) resonator and double split-ring resonators (SRRs) in the middle infrared region (MIR). Both the theoretical calculations according to the coupled harmonic oscillator model and simulation results indicate that the realization of the PIT effect significantly depends on the coupling distance and the coupling strength between the CW resonator and SRRs. In addition, the geometrical parameters of the CW resonator and the number of the graphene layers can alter the optical response of the graphene structure. Particularly, compared with the metal-based metamaterial, the PIT effect realized in the proposed metasurface can be flexibly modulated without adding other actively controlled materials and reconstructing the structure by taking advantage of the tunable complex surface conductivity of the graphene. These results could find significant applications in ultrafast variable optical attenuators, sensors and slow light devices.

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 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.

scholarly journals Dual-Tunable Polarization Insensitive Electromagnetically Induced Transparency in Metamaterials

2021 ◽  
Author(s):  
Renxia Ning ◽  
Zhiqiang Xiao ◽  
Zhenhai Chen ◽  
Wei Huang
Keyword(s):  
Vanadium Dioxide ◽  
Mode Coupling ◽  
Slow Light ◽  
Chemical Potential ◽  
Electromagnetically Induced Transparency ◽  
Dark Mode ◽  
Potential Applications ◽  
Polarization Insensitive ◽  
Terahertz Devices ◽  
Induced Transparency

AbstractA multilayer structure of a square ring of graphene with nesting vanadium dioxide (VO2) was investigated in this study. This structure exhibits electromagnetically induced transparency (EIT), which stems from a bright mode coupling with a dark mode. The permittivity values of graphene and VO2 can be modulated via chemical potential and temperature, respectively. The EIT effect can be tuned based on the chemical potential of graphene and temperature of VO2, resulting in a dual-tunable EIT effect. Simulation results confirmed that this dual-tunable EIT phenomenon is insensitive to polarization. These results may have potential applications in terahertz devices, such as slow light devices, switching devices, and sensors.

Dual plasmonically induced transparency and ultra-slow light effect in m-shaped graphene-based terahertz metasurfaces

2019 ◽  
Vol 12 (12) ◽  
pp. 126001 ◽  
Author(s):  
Enduo Gao ◽  
Zhimin Liu ◽  
Hongjian Li ◽  
Hui Xu ◽  
Zhenbin Zhang ◽  
...  
Keyword(s):  
Slow Light ◽  
Light Effect ◽  
Induced Transparency ◽  
Plasmonically Induced Transparency

Tunable plasmonic-induced transparency based on stub-coupled cascade ring resonator with electro-optical material

2019 ◽  
Vol 33 (18) ◽  
pp. 1950206
Author(s):  
Fang Chen ◽  
Huafeng Zhang ◽  
Lihui Sun ◽  
Jijun Li ◽  
Chunchao Yu
Keyword(s):  
Slow Light ◽  
Ring Resonator ◽  
Optical Switch ◽  
Fdtd Method ◽  
Optical Material ◽  
Ring Resonators ◽  
Refractive Index Sensor ◽  
External Voltage ◽  
All Optical Switch ◽  
Induced Transparency

The electrical control of plasmonic-induced transparency (PIT) via a resonator waveguide system is presented. The proposed structure is composed of a stub and cascade ring resonator. The ring and the stub resonator are filled with electro-optical material which can control the resonance frequency by the external voltage. Two-dimensional finite difference time domain (2D FDTD) method is used to calculate the transmission and field distribution. Single PIT is investigated both by FDTD and Coupled Mode Theory (CMT). The proposed PIT can be tuned by changing the external voltage or the geometric parameters. Double and triple PIT can be obtained by introducing more ring resonators and can be tuned by external voltage. The proposed plasmonic structure may have application in slow light device, nanoscale filter, all-optical switch and refractive index sensor.

Investigating the direct coupling between plasmonic cavities in the case of the second-order resonant mode

2014 ◽  
Vol 28 (27) ◽  
pp. 1450217
Author(s):  
Zhihui He ◽  
Hongjian Li ◽  
Shiping Zhan ◽  
Guangtao Cao ◽  
Boxun Li
Keyword(s):  
Coupling Strength ◽  
Slow Light ◽  
Electromagnetically Induced Transparency ◽  
Resonant Mode ◽  
Second Order ◽  
Direct Coupling ◽  
Dark Mode ◽  
High Order Resonance ◽  
Light Effects ◽  
Induced Transparency

In this paper, we present a metal-dielectric-metal (MDM) waveguide side-coupled with bright-dark-bright mode cavities and double bright-dark mode cavities. The former shows a prominent plasmonic analogue of electromagnetically induced transparency (EIT) spectra response, the latter shows double plasmonic analogue of EIT spectra response. The direct coupling strength between bright and dark mode resonators in the case of the second-order resonant mode is investigated in detail in our researches. The transmission spectrum and the slow light effects as a function of the cavity–cavity separation between resonators are further studied. Our researches investigate the coupling strength effects on the transmission and scattering properties in the case of the high-order resonance mode, which may provide a guideline for the control of light in highly integrated optical circuits.

scholarly journals Tunable Metamaterial with Gold and Graphene Split-Ring Resonators and Plasmonically Induced Transparency

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 7 ◽  
Author(s):  
Qichang Ma ◽  
Youwei Zhan ◽  
Weiyi Hong
Keyword(s):  
Electromagnetically Induced Transparency ◽  
Transparency Window ◽  
Ring Resonators ◽  
Metamaterial Structure ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Electrostatic Gating ◽  
Tunable Metamaterial ◽  
Induced Transparency ◽  
Plasmonically Induced Transparency

In this paper, we propose a metamaterial structure for realizing the electromagnetically induced transparency effect in the MIR region, which consists of a gold split-ring and a graphene split-ring. The simulated results indicate that a single tunable transparency window can be realized in the structure due to the hybridization between the two rings. The transparency window can be tuned individually by the coupling distance and/or the Fermi level of the graphene split-ring via electrostatic gating. These results could find significant applications in nanoscale light control and functional devices operating such as sensors and modulators.

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