Open AccessMechanical modulation of terahertz wave via buckled carbon nanotube sheets
Author(s) -
ShiTong Xu,
Linlin Mou,
Fei Fan,
Sai Chen,
Zhikai Zhao,
Dong Xiang,
Mário de Andrade,
Zunfeng Liu,
Shengjiang Chang
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.028738
Subject(s) - terahertz radiation , materials science , optics , carbon nanotube , polarization (electrochemistry) , optoelectronics , natural rubber , polarizer , modulation (music) , transmittance , nanotechnology , composite material , physics , birefringence , acoustics , chemistry
Manipulation of terahertz (THz) wave plays an important role in THz imaging, communication, and detection. The difficulty in manipulating the THz wave includes single function, untunable, and inconvenient integration. Here, we present a mechanically tunable THz polarizer by using stretchable buckled carbon nanotube sheets on natural rubber substrate (BCNTS/rubber). The transmittance and degree of polarization of THz wave can be modulated by stretching the BCNTS/rubber. The experiments showed that the degree of polarization increased from 17% to 97%, and the modulation depth reached 365% in the range of 0.2-1.2 THz, as the BCNTS/rubber was stretched from 0% to 150% strain. These changes can be also used for high strain sensing up to 150% strain, with a maximum sensitivity of 2.5 M/S. A spatial modulation of THz imaging was also realized by stretching and rotating BCNTS/rubber. The theoretical analysis and numerical modeling further confirm the BCNTS/rubber changes from weak anisotropic to highly anisotropic structure, which play key roles in THz wave modulation. This approach for active THz wave manipulation can be widely used in polarization imaging, wearable material for security, and highly sensitive strain sensing.