scholarly journals Design of Tunable Terahertz Metamaterial Sensor with Single- and Dual-Resonance Characteristic

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2212
Author(s):  
Jiahao Yang ◽  
Yu-Sheng Lin
Keyword(s):  
Refractive Index ◽  
Tuning Range ◽  
High Efficiency ◽  
Ring Resonators ◽  
Frequency Range ◽  
Split Ring ◽  
Resonance Characteristic ◽  
Dual Resonance ◽  
Selective Detectors ◽  
Refractive Index Sensors

We present two types of refractive index sensors by using tunable terahertz (THz) metamaterial (TTM) based on two concentric split-ring resonators (SRRs) with different splits. By modifying the distance between SRRs and substrate, TTM shows tunable single- and dual-resonance characteristic. The maximum tuning range of resonance is 0.432 THz from 0.958 THz to 1.390 THz. To demonstrate a great flexibility of TTM in real application, TTM device is exposed on the surrounding ambient with different refractive index (n). The sensitivity of TTM can be enhanced by increasing SRR height, which is increased from 0.18 THz/RIU to 1.12 THz/RIU under the condition of n = 1.1. These results provide a strategy to improve the sensing performance of the metamaterial-based sensing device by properly arranging the geometric position of meta-atoms. The proposed TTM device can be used for tunable filters, frequency-selective detectors, and tunable high-efficiency sensors in the THz frequency range.

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.

Analytical circuit model for split ring resonators in the far infrared and optical frequency range

Metamaterials ◽  
2009 ◽  
Vol 3 (2) ◽  
pp. 57-62 ◽  
Author(s):  
V. Delgado ◽  
O. Sydoruk ◽  
E. Tatartschuk ◽  
R. Marqués ◽  
M.J. Freire ◽  
...  
Keyword(s):  
Far Infrared ◽  
Circuit Model ◽  
Ring Resonators ◽  
Optical Frequency ◽  
Frequency Range ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Optical Frequency Range

Negative Refractive Index of Meta-materials at Optical Frequencies

2006 ◽  
Vol 964 ◽  
Author(s):  
S. Anantha Ramakrishna ◽  
Sangeeta Chakrabarti
Keyword(s):  
Refractive Index ◽  
Negative Refractive Index ◽  
Magnetic Activity ◽  
Ring Resonators ◽  
Split Ring ◽  
Complex Behaviour ◽  
High Frequencies ◽  
Displacement Currents ◽  
Very High Frequencies ◽  
Very High

ABSTRACTScaling the performance of metamaterials to obtain negative refractive index at optical frequencies has been of great interest. One of the great barriers to the scaling is that real currents cannot be driven at very high frequencies and one is more dependent on displacement currents to generate negative magnetic permeability. Moreover to keep the dimensions of the metamaterials physically accessible, the structural lengthscales of the metamaterials begin approach the wavelength of the radiation in free space and homogenisation is often questionable. Here we will show that metamaterials such as Split ring resonators in these high frequency limits exhibit complex behaviour. Magnetic activity and Negative refractive index behaviour can, indeed, be obtained at optical frequencies but will need to be interpreted very carefully. The plasmonic nature of the metallic system and excitation needs to be considered in detail.

scholarly journals Chiral metamaterials with negative refractive index based on four “U” split ring resonators

2010 ◽  
Vol 97 (8) ◽  
pp. 081901 ◽  
Author(s):  
Zhaofeng Li ◽  
Rongkuo Zhao ◽  
Thomas Koschny ◽  
Maria Kafesaki ◽  
Kamil Boratay Alici ◽  
...  
Keyword(s):  
Refractive Index ◽  
Negative Refractive Index ◽  
Ring Resonators ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Chiral Metamaterials

scholarly journals Nanofabrication of planar split ring resonators for negative refractive index metamaterials in the infrared range

2006 ◽  
Vol 71 (6) ◽  
pp. 695-703 ◽  
Author(s):  
Zoran Jaksic ◽  
Dana Vasiljevic-Radovic ◽  
Milan Maksimovic ◽  
Milija Sarajlic ◽  
Zoran Djuric
Keyword(s):  
Refractive Index ◽  
Negative Refractive Index ◽  
Building Blocks ◽  
Ring Resonators ◽  
Infrared Range ◽  
Process Conditions ◽  
Split Ring ◽  
Crystal Silicon ◽  
Split Ring Resonators ◽  
Positive Photoresist

Experimental nanofabrication of planar structures for one-dimensional metamaterials designed to achieve a negative effective refractive index in the mid-infrared range (5-10 micrometers) was performed. Double split ring and complementary double split ring resonators (SRR and CSRR) with square and circular geometries, were chosen to be fabricated since these are the basic building blocks to achieve a negative effective dielectric permittivity and magnetic permeability. Scanning probe nanolithography with z-scanner movement was used to fabricate straight-line and curvilinear segments with a line width of 80-120 nm. The geometries were delineated in 20 nm thin silver layers sputter-deposited on a positive photoresist substrate spin-coated on polished single crystal silicon wafers, as well as on polycarbonate slabs. The morphology of the structures was characterized by atomic force microscopy. The feature repeatibility was 60-150 nm, depending on the process conditions and the feature complexity. The nanolithographic groove depth in different samples ranged from 4 nm to 80 nm.

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