Abstract-Tunable reflecting terahertz filter based on chirped metamaterial structure

• Jing Yang
• , Cheng Gong
• , Lu Sun
• , Ping Chen
• , Lie Lin
•  & Weiwei Liu

http://www.nature.com/articles/srep38732
Tunable reflecting terahertz bandstop filter based on chirped metamaterial structure is demonstrated by numerical simulation. In the metamaterial, the metal bars are concatenated to silicon bars with different lengths. By varying the conductivity of the silicon bars, the reflectivity, central frequency and bandwidth of the metamaterial could be tuned. Light illumination could be introduced to change the conductivity of the silicon bars. Numerical simulations also show that the chirped metamaterial structure is insensitive to the incident angle and polarization-dependent. The proposed chirped metamaterial structure can be operated as a tunable bandstop filter whose modulation depth, bandwidth, shape factor and center frequency can be controlled by light pumping.

Abstract-3D printed low-loss THz waveguide based on Kagome photonic crystal structure

Jing Yang, Jiayu Zhao, Cheng Gong, Haolin Tian, Lu Sun, Ping Chen, Lie Lin, and Weiwei Liu

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-24-20-22454

A low-loss hollow core terahertz waveguide based on Kagome photonic crystal structure has been designed and fabricated by 3D printing. The 3D printed waveguide has been characterized by using THz time-domain spectroscopy. The results demonstrate that the obtained waveguide features average power propagation loss of 0.02 cm−1 for 0.2-1.0 THz (the minimum is about 0.002 cm−1 at 0.75 THz). More interesting, it could be simply mechanically spliced without any additional alignment, while maintaining the excellent performance. The 3D printing technique will be a promising solution to fabricate Kagome THz waveguide with well controllable characteristics and low cost.

© 2016 Optical Society of America

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Abstract-Graphene-based tunable polarization sensitive terahertz metamaterial absorber

• Guangsheng Deng, 
• Ping Chen, 
• Jun Yang, 
• Zhiping Yin, 
• Longzhen Qiu

• Academy of Photoelectric Technology, Hefei University of Technology, Hefei 230009, China

Received 2 February 2016, Revised 4 May 2016, Accepted 27 May 2016, Available online 9 June 2016

http://www.sciencedirect.com/science/article/pii/S0030401816304680

A tunable metamaterial absorber composed of a metal ground plane, a SiO₂ dielectric spacer, a graphene layer and a metal pattern layer, which is polarization sensitive is numerically proposed at terahertz (THz) frequencies. Our calculated results show that when the Fermi level of graphene is fixed at 0.7 eV, the absorptivities for x-polarized wave are about 0.985 at 6.42 THz, and 0.991 at 8.37 THz, respectively, while the absorptivity for y-polarized wave is about 0.99 at 7.22 THz. Moreover, the calculated electric field and surface current distributions, along with power loss distributions enable us to deeply understand the physical mechanism of resonance absorption. More importantly, absorption spectra at different Fermi levels of graphene and different incident angles are displayed and tuning functions are discussed in detail. This work may provide a further step in the development of potential applications based on metamaterial absorber, such as THz polarization imaging, THz sensing and polarization multiplexing.