Abstract-SU-8 based planar metamaterials with fourfold symmetry as selective terahertz absorbers

B. Grześkiewicz,  A. Sierakowski, J. Marczewski, N. Pałka,  E .Wolarz,

https://www.sciencedirect.com/science/article/abs/pii/S1230340218300532

We report on the absorption properties of polarization-insensitive transmissive and reflective metamaterial absorbers based on two planar aluminium periodic structures and SU-8 epoxy resist. These absorbers were investigated using numerical simulation and experimental methods in the terahertz range (below 2 THz). SU-8 is a very promising organic material for dielectric layers in planar metamaterials, because its application simplifies the process of fabricating these structures and significantly reduces the fabrication time. The experimental absorption of the metamaterial absorbers has narrowband characteristics that were consistent with the numerical simulations. Power flow analysis in the transmissive metamaterial unit cell shows that the absorption in the terahertz range occurs primarily in the SU-8 layer of the absorber.

Abstract-Dynamically Babinet-invertible metasurface: a capacitive-inductive reconfigurable filter for terahertz waves using vanadium-dioxide metal-insulator transition

Yoshiro Urade, Yosuke Nakata, Kunio Okimura, Toshihiro Nakanishi, Fumiaki Miyamaru, Mitsuo W. Takeda, and Masao Kitano

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-24-5-4405

This paper proposes a reconfigurable planar metamaterial that can be switched between capacitive and inductive responses using local changes in the electrical conductivity of its constituent material. The proposed device is based on Babinet’s principle and exploits the singular electromagnetic responses of metallic checkerboard structures, which are dependent on the local electrical conductivity. Utilizing the heating-induced metal-insulator transition of vanadium dioxide (VO2), the proposed meta-material is designed to compensate for the effect of the substrate and is experimentally characterized in the terahertz regime. This reconfigurable metamaterial can be utilized as a switchable filter and as a switchable phase shifter for terahertz waves.

© 2016 Optical Society of America

Full Article  |  PDF Article

Abstract-Plasmon-induced transparency in terahertz planar metamaterials

• Xu Chen^a, b, 
• Wen-Hui Fan^a, , 

• ^a State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119, China
• ^b University of Chinese Academy of Sciences, Beijing 100049, China

Received 11 June 2015, Revised 17 July 2015, Accepted 23 July 2015, Available online 30 July 2015

http://www.sciencedirect.com/science/article/pii/S0030401815006616

A planar metamaterial structure with plasmon-induced transparency effect in terahertz region is proposed and systematic numerical study is presented in this paper. The metamaterial structure is comprised of two different spilt-ring resonators in the same plane. With the destructive interference coupling between these two split-ring resonators, the proposed metamaterial structure exhibits a large transparency window within a broad absorption spectra. Moreover, the origin of transparency window with extremely low absorption and strong dispersion is clarified by two coupled Lorentzian resonators analytical model, and verified by accurate simulation of the electromagnetic wave propagation in the metamaterial structure. The proposed metamaterial opens up the avenue to design micro-sized functional devices used in switching, modulation, and slowing down terahertz waves.

Abstract-Magnetic-coupling induced transparency in a planar terahertz metamaterial

Ming Li Wan

Corresponding author.

Electric and Information Engineering College, Pingdingshan University, Pingdingshan, Henan Province 467000, P. R. China

Shu Qing Yuan

Electric and Information Engineering College, Pingdingshan University, Pingdingshan, Henan Province 467000, P. R. China

Yue Li Song

Electric and Information Engineering College, Pingdingshan University, Pingdingshan, Henan Province 467000, P. R. China

New Pv-energy Engineering Research Center, Pingdingshan University, Pingdingshan, Henan Province 467000, P. R. China

Yong Li

Electric and Information Engineering College, Pingdingshan University, Pingdingshan, Henan Province 467000, P. R. China

Mingli Tian

Electric and Information Engineering College, Pingdingshan University, Pingdingshan, Henan Province 467000, P. R. China

Feng Qun Zhou

Electric and Information Engineering College, Pingdingshan University, Pingdingshan, Henan Province 467000, P. R. China

 http://www.worldscientific.com/doi/abs/10.1142/S0217979215501143?src=recsys&

In this paper, we demonstrate that an electromagnetically induced transparency (EIT)-like behavior is induced by the coupling of two magnetic resonances in a planar terahertz (THz) metamaterial structure, which consists of a U-shaped split ring (USR) as one bright resonator and a cut wire pair (CWP) as one dark resonator. It is found that the EIT-like spectral response is insensitive to the lateral distance between the two magnetic resonators, whereas an on-to-off modulation of the amplitude of the transparency window can be achieved by moving the USR vertically along the CWP. The underlying physical mechanism is mainly attributed to magneto-inductive excitation of the CWP. This investigation may provide an insight of the role of magnetic coupling in achieving EIT-like effect, inspiring interest in the developments of magnetically tunable transparency metamaterial for a wide range of optical devices with switching and modulation capabilities.

Abstract-Stable terahertz toroidal dipolar resonance in a planar metamaterial

1. Chunfeng Ding^1,2,3, 
2. Linkun Jiang^1,2,
3. Chongling Sun⁴, 
4. Liang Wu^1,2, 
5. Degang Xu^1,2, 
6. Guizhong Zhang^1,2 and
7. Jianquan Yao^1,2,*

Article first published online: 11 MAR 2015

DOI: 10.1002/pssb.201552006

http://onlinelibrary.wiley.com/doi/10.1002/pssb.201552006/abstract

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, 

In this paper, we proposed and fabricated a planar terahertz (THz) metamaterial that is composed of four asymmetric split-ring resonators (ASRRs) coated with two polyimide layers. Simulation and experimental results show that a Fano-shaped toroidal dipolar resonance at 0.42 THz is acquired from the metamaterial. Further analysis indicates that the toroidal dipolar resonance originates from the coupling of the four ASRRs, and the polyimide coating layers on both sides of the structure play key role in keeping the resonance frequency unchanged. From the designed metamaterials, a confined electromagnetic field inside the dielectric medium with a subwavelength-scale toroidal geometry is observed, and a strong confined E-field component at the toroidal dipole center with its orientation perpendicular to the H-vortex plane can also be numerically acquired. This planar metamaterial would open up an avenue for potential applications in the terahertz regime.