scholarly journals Asymmetric Transmission in a Mie-Based Dielectric Metamaterial with Fano Resonance

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1003 ◽  
Author(s):  
Xiaobo Wang ◽  
Haohua Li ◽  
Ji Zhou

Chiral metamaterials with asymmetric transmission can be applied as polarization-controlled devices. Here, a Mie-based dielectric metamaterial with a spacer exhibiting asymmetric transmission of linearly polarized waves at microwave frequencies was designed and demonstrated numerically. The unidirectional characteristic is attributed to the chirality of the metamolecule and the mutual excitation of the Mie resonances. Field distributions are simulated to investigate the underlying physical mechanism. Fano-type resonances emerge near the Mie resonances of the constituents and come from the destructive interference inside the structure. The near-field coupling further contributes to the asymmetric transmission. The influences of the lattice constant and the spacer thickness on the asymmetric characteristics were also analyzed by parameter sweeps. The proposed Mie-based metamaterial is of a simple structure, and it has the potential for applications in dielectric metadevices, such as high-performance polarization rotators.

Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3235-3242 ◽  
Author(s):  
Tingting Lv ◽  
Xieyu Chen ◽  
Guohua Dong ◽  
Meng Liu ◽  
Dongming Liu ◽  
...  

AbstractPolarization conversion dichroism is of particular interest in manipulating the polarization state of light, whereas high-performance asymmetric transmission (AT) of linearly polarized waves is still inaccessible in the terahertz range. Here, a bilayer chiral metamaterial consisting of orthogonally chained S-shaped patterns with broken symmetry along the light propagation direction is proposed and demonstrated experimentally to realize a dual-band dichroic AT effect for linearly polarized terahertz waves. The AT effects are robust across a wide range of incident angles. The observed strong AT can be theoretically explained by a multiple reflection and transmission interference model and the transfer matrix method. The proposed bilayer chiral metamaterial may have broad applications in polarization manipulation, chiral biosensing and direction-dependent information processing.


2017 ◽  
Vol 121 (3) ◽  
pp. 033103 ◽  
Author(s):  
Shenying Fang ◽  
Kang Luan ◽  
Hui Feng Ma ◽  
Wenjin Lv ◽  
Yuxiang Li ◽  
...  

2014 ◽  
Vol 28 (32) ◽  
pp. 1450250 ◽  
Author(s):  
Furkan Dincer ◽  
Muharrem Karaaslan ◽  
Oguzhan Akgol ◽  
Emin Unal ◽  
Cumali Sabah

In this study, a dynamic chiral metamaterial (MTM) structure leading to an asymmetric electromagnetic (EM) wave transmission for linear polarization is presented. The structure is composed of square-shaped resonator with gaps on both sides of a dielectric substrate with a certain degree of rotation. The dynamic structure is adjustable via various parameters to fit any desired frequency ranges. Theoretical and experimental analysis of the proposed structure are conducted and given in detail. The suggested model can provide constant chirality over a certain frequency band and thus, it can be used to design myriad novel devices such as EM transmission and antireflection filters, and polarization rotators for desired frequency regimes.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2410
Author(s):  
Wenbing Liu ◽  
Lirong Huang ◽  
Jifei Ding ◽  
Chenkai Xie ◽  
Yi Luo ◽  
...  

Asymmetric optical transmission plays a key role in many optical systems. In this work, we propose and numerically demonstrate a dielectric–metal metasurface that can achieve high-performance asymmetric transmission for linearly polarized light in the near-infrared region. Most notably, it supports a forward transmittance peak (with a transmittance of 0.70) and a backward transmittance dip (with a transmittance of 0.07) at the same wavelength of 922 nm, which significantly enhances operation bandwidth and the contrast ratio between forward and backward transmittances. Mechanism analyses reveal that the forward transmittance peak is caused by the unidirectional excitation of surface plasmon polaritons and the first Kerker condition, whereas the backward transmittance dip is due to reflection from the metal film and a strong toroidal dipole response. Our work provides an alternative and simple way to obtain high-performance asymmetric transmission devices.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shuang Li ◽  
Li-rong Huang ◽  
Yong-hong Ling ◽  
Wen-bing Liu ◽  
Chun-fa Ba ◽  
...  

AbstractAsymmetric transmission (AT) devices are fundamental elements for optical computing and information processing. We here propose an AT device consisting of a pair of coupled complementary subwavelength gratings. Different from previous works, asymmetric dielectric environment is employed for unidirectional excitation of surface plasmon polaritons (SPPs) and thus asymmetric optical transmission, and near-field coupling effect inherent in the coupled complementary structure is exploited to enhance forward transmission and AT behavior, and determine operation bandwidth as well. The influence of asymmetric dielectric environment, effect of vertical and lateral couplings, interactions of electric- and magnetic-dipole moments and the realization of Kerker conditions, are investigated in depth to unearth the AT mechanism and performance. High-performance AT with large forward transmittance of 0.96 and broad bandwidth of 174 nm is achieved at wavelength 1250 nm. Our work helps people to gain a better understanding of near-filed coupling effect in coupled complementary structures, expand their application fields, and it also offers an alternate way to high-performance AT devices.


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