Study of dual-spectral electromagnetically induced transparency in bright-dark mode coupling metamaterials

Author(s):  
Sen Hu ◽  
He Lin Yang ◽  
Jiao Chen ◽  
Xiao Jun Huang
Author(s):  
Renxia Ning ◽  
Zhiqiang Xiao ◽  
Zhenhai Chen ◽  
Wei Huang

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.


2016 ◽  
Vol 2 (2) ◽  
pp. e1501142 ◽  
Author(s):  
Xueqian Zhang ◽  
Quan Xu ◽  
Quan Li ◽  
Yuehong Xu ◽  
Jianqiang Gu ◽  
...  

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.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1350
Author(s):  
Qiao Wang ◽  
Kaili Kuang ◽  
Huixuan Gao ◽  
Shuwen Chu ◽  
Li Yu ◽  
...  

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.


Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1359 ◽  
Author(s):  
Haoying Sun ◽  
Lin Zhao ◽  
Jinsong Dai ◽  
Yaoyao Liang ◽  
Jianping Guo ◽  
...  

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.


2014 ◽  
Vol 28 (27) ◽  
pp. 1450217
Author(s):  
Zhihui He ◽  
Hongjian Li ◽  
Shiping Zhan ◽  
Guangtao Cao ◽  
Boxun Li

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.


2021 ◽  
Author(s):  
Tiantian Zheng ◽  
Zhongyin Xiao ◽  
Mingming Chen ◽  
Xiang Miao ◽  
Xiaoyu Wang

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.


2016 ◽  
Vol 109 (21) ◽  
pp. 211103 ◽  
Author(s):  
Prakash Pitchappa ◽  
Manukumara Manjappa ◽  
Chong Pei Ho ◽  
Ranjan Singh ◽  
Navab Singh ◽  
...  

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