Book Abstract-Terahertz Metamaterials and Metadevices

Author: Xingcun Colin Tong

https://www.springerprofessional.de/en/terahertz-metamaterials-and-metadevices/15059858

Terahertz metamaterials are designed to interact at terahertz (THz) frequencies, which is usually defined as 0.1–10 THz. Terahertz regime is located at the interface of electronics and photonics where technologies directly translated from microwave and optical regime generally fail to operate. This is so-called terahertz gap that is caused mainly by weak or nonexistent material response at terahertz frequencies. Coupled with various passive and active media, terahertz metamaterials offer a solution to fill the terahertz gap. Moreover, there is a possibility that terahertz metadevices will become the next enabling technological breakthrough in terahertz technologies, particularly desirable to raise the performance and functionality of terahertz systems in imaging, sensing, spectroscopy, and nondestructive evaluation. This chapter will give a brief review about manipulation technologies and applications of various terahertz metamaterials and metadevices, such as passive type, active type, and flexible metamaterials and metadevices.

Abstract-Mechanically tunable terahertz graphene plasmonics using soft metasurface

Li Wang, Xin Liu, Jianfeng Zang,
http://iopscience.iop.org/article/10.1088/2053-1583/3/4/041007/meta;jsessionid=EB8BDE24B94CFE0F02A24EBB8E8B9051.c1.iopscience.cld.iop.org

This letter presents a new approach to continuously tune the resonances of graphene plasmons in terahertz soft metasurface. The continuous tunability of plasmon resonance is either unachievable in conventional plasmonic materials like noble metals or requires gate voltage regulation in graphene. Here we investigate a simplest form of terahertz metasurface, graphene nanoribbon arrays (GNRAs), and demonstrate the graphene plasmon resonance modes can be tailored by mechanical deformation of the elastomeric substrate using finite element method (FEM). By integrating the electric doping with substrate deformation, we have managed to tune the resonance wavelength from 13.7 to 50.6μm. The 36.9 μm tuning range is nearly doubled compared with that by electric doping regulation only. Moreover, we observe the plasmon coupling effect in GNRAs on waved substrate and its evolution with substrate curvature. A new decoupling mechanism enabled by the out-of-plane separation of the adjacent ribbons is revealed. The out-of-plane setup of plasmonic components extends the fabrication of plasmonic devices into three-dimensional space, which simultaneously increases the nanoribbon density and decreases the coupling strength. Our findings provide an additional degree of freedom to design reconfigurable metasurfaces and metadevices.