Abstract-Tunable multi-resonance of terahertz metamaterial using split-disk resonators

AIP Advances

Daoye Zheng, Xingzhuo Hu,  Yu-Sheng Lin, Chang-Han Chen,

(a) Schematic drawings of SDR-1, SDR-2, and SDR-3 composed of single-, dual-, and triple-SDR layers, respectively. (b) Geometrical denotations of the SDR unit cell. (c) and (d) are cross-sectional views of SDR-2 and SDR-3 along the red dashed-squares of (a), respectively. The thicknesses of all SDR layers are 300 nm. The parameters of D, W, and Ls are kept constant as 60 µm, 4 µm, and 30 µm, respectively.

https://aip.scitation.org/doi/abs/10.1063/1.5139263

We present three tunable multi-resonance of terahertz (THz) metamaterials. They are composed of single-, dual-, and triple-split-disk resonators (SDRs) on Si substrates, which are denoted as SDR-1, SDR-2, and SDR-3, respectively. They exhibit extraordinary electromagnetic characteristics. SDR-1 exhibits polarization-dependence owing to the asymmetrical SDR structure. To increase the flexibility and applicability of SDR configuration, SDR-2 and SDR-3 are presented to modify the distances between the SDR layers. By moving the top SDR layer of SDR-2, a controllable resonance with a 0.32 THz shifting and tunable free spectrum range (FSR) of 0.15 THz at transverse magnetic mode is achieved, while an electromagnetically induced transparency-like effect appears at the transverse electric mode. The spectral bandwidth of SDR-3 can be tuned to 0.10 THz, and the resonant intensity becomes controllable by moving the middle SDR layer of SDR-3. Furthermore, by moving the top SDR layer of SDR-3, the tuning ranges of resonance, FSR, and bandwidth of SDR-3 are 0.23 THz, 0.20 THz, and 0.08 THz, respectively. Such designs of SDR configurations provide a high-efficient THz resonator in the THz-wave applications such as filters, switches, polarizers, sensors, imaging, and so on.

Abstract-Actively tunable terahertz metamaterial with single-band and dual-band switching characteristic

• Xingzhuo Hu, 
• Daoye Zheng & 
• Yu-Sheng Lin, 
 
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• https://link.springer.com/article/10.1007%2Fs00339-019-3274-5
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We present a design of tunable terahertz (THz) metamaterial (TTM) with single-band and dual-band filtering and switching characteristics. The proposed device is composed of face-to-face split-ring resonator (SRR) and a central bar. By moving the SRRs to change the gap between SRRs and central bar, the free spectrum ranges (FSR) could be bi-directionally broadened 0.14 THz and narrowed 0.19 THz at TE and TM modes, respectively. To control the coplanar moving central bar, the electromagnetic response of TTM device exhibits polarization-dependent characteristic. TTM shows the switching characteristic between single-band to dual-band resonance at TE mode and exhibits resonance-insensitive to the displacement of central bar at TM mode. These results open an avenue to be potentially used for detector, sensor, and switch in the THz-wave applications.