Terahertz Response of Metamaterial Split-Ring Resonators: Numerical Analysis and Topology Design

Using numerical simulation techniques, the response characteristics of metamaterials split-ring resonators (SRRs) in terahertz region are analyzed. We examine the transmission and dispersion characteristics of several SRRs and show that there are two significant resonances corresponding to electric response and magnetic response, respectively. Based on the topology optimization technique, a terahertz magnetic response of metamaterial for the goal of maximum bandwidth is performed, the results seem to imply that the SRRs structure is the most reasonable topological form for broad magnetic resonance in THz band.

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Study on the Electromagnetic Responses of Split Ring Resonator in THz Regions

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.760-762.302 ◽

2013 ◽

Vol 760-762 ◽

pp. 302-305

Author(s):

Wei Kai Xu ◽

Ying Chun Tang ◽

Wei Wang

Keyword(s):

Electric Field ◽

Ring Resonator ◽

Split Ring Resonator ◽

Field Vector ◽

Electric Response ◽

Electric Field Vector ◽

Split Ring ◽

Response Characteristics ◽

Terahertz Region ◽

Simulation Techniques

By using the numerical simulation techniques, the response characteristics of single split-ring resonator (SRR) in a broadband terahertz region are analyzed. We examine the transmission and dispersion characteristics of the SRR and show that there are different resonances while changing the orientations of electric field vector relative to the gap-bearing sides. Two significant resonances corresponding to electric response and magnetic response will be observed while the electric field vector perpendicular to the gap-bearing side, and only one electric resonance occurs when the electric field vector parallel to the same side. This will be a reference to design the possible terahertz metamaterials.

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Passively Tunable Terahertz Filters Using Liquid Crystal Cells Coated with Metamaterials

Coatings ◽

10.3390/coatings11040381 ◽

2021 ◽

Vol 11 (4) ◽

pp. 381

Author(s):

Wei-Fan Chiang ◽

Yu-Yun Lu ◽

Yin-Pei Chen ◽

Xin-Yu Lin ◽

Tsong-Shin Lim ◽

...

Keyword(s):

Liquid Crystal ◽

Ring Resonators ◽

Maximum Frequency ◽

Split Ring ◽

Split Ring Resonators ◽

Terahertz Region ◽

Resonance Frequencies ◽

Terahertz Communication ◽

Terahertz Sensing ◽

Crystal Cells

Liquid crystal (LC) cells that are coated with metamaterials are fabricated in this work. The LC directors in the cells are aligned by rubbed polyimide layers, and make angles θ of 0°, 45°, and 90° with respect to the gaps of the split-ring resonators (SRRs) of the metamaterials. Experimental results display that the resonance frequencies of the metamaterials in these cells increase with an increase in θ, and the cells have a maximum frequency shifting region of 18 GHz. Simulated results reveal that the increase in the resonance frequencies arises from the birefringence of the LC, and the LC has a birefringence of 0.15 in the terahertz region. The resonance frequencies of the metamaterials are shifted by the rubbing directions of the polyimide layers, so the LC cells coated with the metamaterials are passively tunable terahertz filters. The passively tunable terahertz filters exhibit promising applications on terahertz communication, terahertz sensing, and terahertz imaging.

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Magnetic response of split ring resonators at terahertz frequencies

physica status solidi (b) ◽

10.1002/pssb.200674503 ◽

2007 ◽

Vol 244 (4) ◽

pp. 1181-1187 ◽

Cited By ~ 31

Author(s):

Costas M. Soukoulis ◽

Thomas Koschny ◽

Jiangfeng Zhou ◽

Maria Kafesaki ◽

Eleftherios N. Economou

Keyword(s):

Ring Resonators ◽

Magnetic Response ◽

Split Ring ◽

Split Ring Resonators ◽

Terahertz Frequencies

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Optically Tunable Terahertz Metasurfaces Using Liquid Crystal Cells Coated with Photoalignment Layers

Crystals ◽

10.3390/cryst11091100 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1100

Author(s):

Yi-Hong Shih ◽

Xin-Yu Lin ◽

Harry Miyosi Silalahi ◽

Chia-Rong Lee ◽

Chia-Yi Huang

Keyword(s):

Liquid Crystal ◽

Resonance Frequency ◽

Pump Beam ◽

Frequency Tuning ◽

Ring Resonators ◽

Split Ring ◽

Split Ring Resonators ◽

Terahertz Region ◽

Crystal Cells ◽

Terahertz Filter

An optically tunable terahertz filter was fabricated using a metasurface-imbedded liquid crystal (LC) cell with photoalignment layers in this work. The LC director in the cell is aligned by a pump beam and makes angles θ of 0, 30, 60 and 90° with respect to the gaps of the split-ring resonators (SRRs) of the metasurface under various polarized directions of the pump beam. Experimental results display that the resonance frequency of the metasurface in the cell increases with an increase in θ, and the cell has a frequency tuning region of 15 GHz. Simulated results reveal that the increase in the resonance frequency arises from the birefringence of the LC, and the LC has a birefringence of 0.13 in the terahertz region. The resonance frequency of the metasurface is shifted using the pump beam, so the metasurface-imbedded LC cell with the photoalignment layers is an optically tunable terahertz filter. The optically tunable terahertz filter is promising for applications in terahertz telecommunication, biosensing and terahertz imaging.

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