TST, Vol. 14, No. 2, PP. 31-43

(Invited paper) All-silicon terahertz metamaterials absorber and pesticides sensing

Zijian Cui, Yue Wang ^*, Xiang Zhang, Yongqiang Zhu, and Dachi Zhang
Key Laboratory of Ultrafast Photoelectric Technology and Terahertz Science in Shaanxi, Xi¡¯an University of Technology, 710048, Xi¡¯an, Shaanxi, China
^* Email: wangyue2017@xaut.edu.cn

(Received June 2021)

Abstract: Perfect absorption based on metamaterials at terahertz frequencies range has attracted a great deal of interest in the field of sensing, imaging, bolometers and stealth technology. This review is focused on presenting several recently developed absorbers based on all-silicon metamaterials, such as single-band, dual-band, multi-band and broadband absorbers. The partial physical mechanisms and optical tunability corresponding to the absorption are also reported. Furthermore, the presented absorbers can be used to detect the concentration of trace pesticides, and a good linear regression coefficient was obtained between the absorption amplitude and the concentration. Notably, the presented all-silicon metamaterials perfect absorbers are compatible with COMS processing which is beneficial to promote the development of terahertz functional devices.

Keywords: Terahertz absorber, Metamaterials, Sensing, All-silicon

doi:

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TST, Vol. 14, No. 2, PP. 44-51

(Invited paper) Low-voltage driven graphene-loaded metal wire grating device in total internal reflection geometry for broadband THz modulation

Xudong Liu, Hao Chen, Teng Li, and Yiwen Sun ^*
Department of Biomedical Engineering, School of Medicine, Shenzhen University, Shenzhen 518060, China
^* Email: ywsun@szu.edu.cu

(Received June 2021)

Abstract: Terahertz modulators with capability of both intensity and phase are essential for THz imaging and communication systems. The low-voltage driven THz modulation technique is crucial for integrating the modulators with electronics components. There is still a lack of broadband devices able to achieve both amplitude and phase modulation with low voltage, due to the underlying physics behind existing approaches. Here, we demonstrate a graphene-loaded metal wire grating THz modulator in the total internal reflection geometry to achieve intensity modulation of 80% and phase modulation of 70 degree within 3 volts gate voltage. Quite different from using the strategy of metamate-rials based on the electromagnetic resonance effects, our design has performed a broadband modulation for over 1 THz bandwidth.

Keywords: Terahertz, Graphene, Metal wire grating, Broadband modulation

doi:

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