Abstract-Ultrasensitive specific terahertz sensor based on tunable plasmon induced transparency of a graphene micro-ribbon array structure

Pei-ren Tang, Jiang Li, Liang-hui Du, Qiao Liu, Qi-xian Peng, Jian-heng Zhao, Bing Zhu, Ze-ren Li, Li-guo Zhu,

Fig. 1 Conceptual view of the PIT-sensor based on graphene micro-ribbon (GMR). The electromagnetic field is mainly concentrated at the edges of GMR, when excited by a THz wave, leading to the enhanced interaction between THz wave and the analyte. The tunability of the PIT sensor is achieved by changing the bias voltages (V1 and V2) applied on the two sets of GMR arrays.

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-26-23-30655

We proposed an ultrasensitive specific terahertz sensor consisting of two sets of graphene micro-ribbon with different widths. The interference between the plasmon resonances of the wide and narrow graphene micro-ribbons gives rise to the plasmon induced transparency (PIT) effect and enables ultrasensitive sensing in terahertz region. The performances of the PIT sensor have been analyzed in detail considering the thickness and refractive index sensing applications using full wave electromagnetic simulations. Taking advantage of the electrical tunability of graphene’s Fermi level, we demonstrated the specific sensing of benzoic acid with detection limit smaller than 6.35 µg/cm2. The combination of specific identification and enhanced sensitivity of the PIT sensor opens exciting prospects for bio/chemical molecules sensing in the terahertz region.

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Abstract-Graphene-based tunable terahertz plasmon-induced transparency metamateria

Xiaolei Zhao,   Cai Yuan,   Lin Zhu and   Jian Quan Yao  

Nanoscale, 2016, Accepted Manuscript

DOI: 10.1039/C5NR07114C



http://pubs.rsc.org/en/content/articlelanding/2016/nr/c5nr07114c#!divAbstract

A novel terahertz plasmon induced transparency (PIT) metamaterial structure consisting of single-layered graphene microstructures is proposed and numerically studied in this paper. A pronounced transparency peak is obtained in the transmission spectrum resulting from the destructive interference between the graphene dipole and monopole antennas. Further investigations have shown that the spectral location and lineshape of the transparency peak can be dynamically controlled by tuning the Fermi level in graphene. Since the monopole antennas in our designed structure exist in a continuous form, it is much more convenient to realize the tunablity by applying a gate voltage than those structures with discrete graphene patterns. This work may open up new avenue for designing tunable terahertz functional devices and slow light devices.