scholarly journals Electromagnetically Induced Transparency-Like Effect by Dark-Dark Mode Coupling

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1350
Author(s):  
Qiao Wang ◽  
Kaili Kuang ◽  
Huixuan Gao ◽  
Shuwen Chu ◽  
Li Yu ◽  
...  
Keyword(s):  
Mode Coupling ◽  
Slow Light ◽  
Electromagnetically Induced Transparency ◽  
Research Area ◽  
Destructive Interference ◽  
Dark Mode ◽  
Metal Grating ◽  
Layer 4 ◽  
Induced Transparency ◽  
Waveguide Resonance

Electromagnetically induced transparency-like (EIT-like) effect is a promising research area for applications of slow light, sensing and metamaterials. The EIT-like effect is generally formed by the destructive interference of bright-dark mode coupling and bright-bright mode coupling. There are seldom reports about EIT-like effect realized by the coupling of two dark modes. In this paper, we numerically and theoretically demonstrated that the EIT-like effect is achieved through dark-dark mode coupling of two waveguide resonances in a compound nanosystem with metal grating and multilayer structure. If we introduce |1〉, | 2 〉 and | 3 〉 to represent the surface plasmon polaritons (SPPs) resonance, waveguide resonance in layer 2, and waveguide resonance in layer 4, the destructive interference occurs between two pathways of | 0 〉 → | 1 〉 → | 2 〉 and | 0 〉 → | 1 〉 → | 2 〉 → | 3 〉 → | 2 〉 , where | 0 〉 is the ground state without excitation. Our work will stimulate more studies on EIT-like effect with dark-dark mode coupling in other systems.

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.

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.

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 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.

ELECTROMAGNETICALLY INDUCED TRANSPARENCY (EIT)-LIKE TRANSMISSION IN ORTHOGONAL-COUPLED SLOT CAVITIES

2012 ◽  
Vol 27 (02) ◽  
pp. 1350009 ◽  
Author(s):  
YINGHUI GUO ◽  
LIANSHAN YAN ◽  
WEI PAN ◽  
BIN LUO ◽  
KUNHUA WEN ◽  
...  
Keyword(s):  
Near Infrared ◽  
Electromagnetically Induced Transparency ◽  
Fdtd Method ◽  
Infrared Range ◽  
Geometrical Parameters ◽  
Destructive Interference ◽  
Dark Mode ◽  
Horizontal Cavity ◽  
Induced Transparency ◽  
Vertical Cavity

The transmission characteristics and electromagnetic responses of orthogonal-coupled slot cavities system are investigated with finite difference time domain (FDTD) method. Results show the electromagnetically induced transparency (EIT)-like transmission can be realized in the proposed structure due to the destructive interference between the horizontal cavity (bright mode) and the vertical cavity (dark mode). Moreover, trapped resonance modes in the horizontal cavity can be selective whether to be induced in vertical cavity or not depending on their relative position. Consequently, EIT-like transmission can be obtained in visible and near-infrared range, simultaneously or individually. The corresponding physical mechanisms are discussed in terms of counter profiles of fields | Hz | and coupled mode theory. Influences of the geometrical parameters on EIT-like transmission are also investigated to generate transparency windows with different shape.

scholarly journals Graphene-Modulated Terahertz Metasurfaces for Selective and Active Control of Dual-Band Electromagnetic Induced Reflection (EIR) Windows

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2420
Author(s):  
Xunjun He ◽  
Chenguang Sun ◽  
Yue Wang ◽  
Guangjun Lu ◽  
Jiuxing Jiang ◽  
...  
Keyword(s):  
Active Control ◽  
Slow Light ◽  
Near Field ◽  
Dual Band ◽  
Destructive Interference ◽  
Dark Mode ◽  
Field Coupling ◽  
Control Scheme ◽  
Electrostatic Doping ◽  
Induced Transparency

Currently, metasurfaces (MSs) integrating with different active materials have been widely explored to actively manipulate the resonance intensity of multi-band electromagnetic induced transparency (EIT) windows. Unfortunately, these hybrid MSs can only realize the global control of multi-EIT windows rather than selective control. Here, a graphene-functionalized complementary terahertz MS, composed of a dipole slot and two graphene-integrated quadrupole slots with different sizes, is proposed to execute selective and active control of dual-band electromagnetic induced reflection (EIR) windows. In this structure, dual-band EIR windows arise from the destructive interference caused by the near field coupling between the bright dipole slot and dark quadrupole slot. By embedding graphene ribbons beneath two quadrupole slots, the resonance intensity of two windows can be selectively and actively modulated by adjusting Fermi energy of the corresponding graphene ribbons via electrostatic doping. The theoretical model and field distributions demonstrate that the active tuning behavior can be ascribed to the change in the damper factor of the corresponding dark mode. In addition, the active control of the group delay is further investigated to develop compact slow light devices. Therefore, the selective and active control scheme introduced here can offer new opportunities and platforms for designing multifunctional terahertz devices.

A novel reconfigurable electromagnetically induced transparency based on S-PINs

2018 ◽  
Vol 32 (04) ◽  
pp. 1850030 ◽  
Author(s):  
Feng Xue ◽  
Shao-Bin Liu ◽  
Hai-Feng Zhang ◽  
Yong-Diao Wen ◽  
Xiang-Kun Kong ◽  
...  
Keyword(s):  
Slow Light ◽  
Ring Resonator ◽  
Electromagnetically Induced Transparency ◽  
Split Ring Resonator ◽  
Destructive Interference ◽  
Split Ring ◽  
Simple Method ◽  
Strong Phase ◽  
Phase Dispersion ◽  
Induced Transparency

In this paper, a tunable electromagnetically induced transparency (EIT) based on S-PINs is theoretically analyzed. Unit cell of the structure consists of a cutwire (CW), split ring resonator (SRR), and solid state plasma (SS plasma) patches which are composed of S-PIN array. The destructive interference between the CW and SRR results in a narrowband transparency window accompanied with strong phase dispersion. The proposed design can obtain a tunable EIT with different frequencies range from 12.8 GHz to 16.5 GHz in a simple method by switching these S-PINs on or off selectively. The related parameters of the S-PIN such as the size, carrier concentration, and volt-ampere characteristics have been studied theoretically. The interaction and coupling between two resonators are investigated in detail by the analysis of the current distribution and E-field strength as well. The research results provide an effective way to realize reconfigurable compact slow-light devices.

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