scholarly journals Free-Standing Complementary Asymmetric Metasurface for Terahertz Sensing Applications

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2265 ◽  
Author(s):  
Fatima Taleb ◽  
Ibraheem Al-Naib ◽  
Martin Koch
Keyword(s):  
Significant Interaction ◽  
High Sensitivity ◽  
Ring Resonators ◽  
Free Standing ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Sensing Applications ◽  
Highly Sensitive ◽  
Terahertz Frequencies ◽  
Terahertz Sensing

We designed and tested a highly sensitive metasurface device based on free-standing complementary asymmetric split-ring resonators at terahertz frequencies. It is utilized for sensing a galactose film. We characterized the device using the induced red shift of a Fano resonance observed in the THz transmission. The sensor has a high sensitivity of 91.7 GHz/RIU due to a significant interaction between the galactose overlayer and the metasurface.

scholarly journals Passively Tunable Terahertz Filters Using Liquid Crystal Cells Coated with Metamaterials

Coatings ◽  
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.

Applications of metamaterial sensors: a review

2021 ◽  
pp. 1-15
Author(s):  
Divya Prakash ◽  
Nisha Gupta
Keyword(s):  
Electromagnetic Interaction ◽  
High Sensitivity ◽  
Ring Resonators ◽  
Electromagnetic Properties ◽  
Physical Parameters ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Quality Testing ◽  
Properties Of Materials ◽  
Metamaterial Absorbers

Abstract Sensors based on metamaterial absorbers are very promising when it comes to high sensitivity and quality factor, cost, and ease of fabrication. The absorbers could be used to sense physical parameters such as temperature, pressure, density as well as they could be used for determining electromagnetic properties of materials and their characterization. In this work, an attempt has been made to explore the various possible applications of these sensors. Metamaterial-based sensors are very popular for its diverse applications in areas such as biomedical, chemical industry, food quality testing, agriculture. Split-ring resonators with various shapes and topologies are the most frequently used structures where the sensing principle is based on electromagnetic interaction of the material under test with the resonator. Overcoming the design challenges using metamaterial sensors involving several constraints such as cost, compactness, reusability, ease in fabrication, and robustness is also addressed.

Tunable and switchable resonance in optically-controlled nested metamaterials at terahertz frequencies

2016 ◽  
Vol 30 (03) ◽  
pp. 1650011
Author(s):  
Yong-Li Che ◽  
Xiao-Long Cao ◽  
Jian-Quan Yao
Keyword(s):  
Gallium Arsenide ◽  
Quartz Substrate ◽  
Optical Excitation ◽  
Ring Resonators ◽  
Metallic State ◽  
Frequency Range ◽  
Metamaterial Structure ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Terahertz Frequencies

The asymmetrical nested metamaterial, composed of two split-ring resonators (SRRs) and two embedded gallium arsenide (GaAs) islands placed in the two SRRs, has been elaborately designed on quartz substrate. Its tunable and switchable resonances at terahertz (THz) frequencies are numerically demonstrated here based on different conductivities of GaAs, which can be transformed from semiconductor to metallic state through appropriate optical excitation. Without photoexcitation, our designed metamaterial has three resonance peaks in the range of monitored frequency range, and they are located at 0.813, 1.269 and 1.722 THz, respectively. As the conductivity of the two GaAs islands increases, different new resonances appear and constantly strengthen. Finally, four new resonant points are generated, at 0.432, 0.948, 1.578 and 1.875 THz, respectively. At the same time, the metamaterial structure is changed from the original nested mode to a new integral mode. Applying reversible changing conductivity of semiconductor to push the conversion of resonance, this asymmetrical nested design provides a new instance in application and development of additional THz devices.

scholarly journals TERAHERTZ SENSING APPLICATION BY USING FRACTAL GEOMETRIES OF SPLIT-RING RESONATORS

2013 ◽  
Vol 138 ◽  
pp. 407-419 ◽  
Author(s):  
Yanbing Ma ◽  
Huai-Wu Zhang ◽  
Yuanxun Li ◽  
Yicheng Wang ◽  
Weien Lai
Keyword(s):  
Ring Resonators ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Terahertz Sensing ◽  
Sensing Application

Magnetic response of split ring resonators at terahertz frequencies

2007 ◽  
Vol 244 (4) ◽  
pp. 1181-1187 ◽  
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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