Fabrication of low-loss polycarbonate tube waveguide for broadband terahertz transmission by controlled polymer solution-coating method

Author(s):  
Sheng Liu ◽  
Guoxing Xie ◽  
Shuoyin Yu ◽  
Xuehui Lu ◽  
Chengbin Jing ◽  
...  
2019 ◽  
Vol 9 (11) ◽  
pp. 2351 ◽  
Author(s):  
Da Teng ◽  
Kai Wang ◽  
Zhe Li ◽  
Yongzhe Zhao ◽  
Gao Zhao ◽  
...  

Graphene has been recently proposed as a promising alternative to support surface plasmons with its superior performances in terahertz and mid-infrared range. Here, we propose a graphene-coated elliptical nanowire (GCENW) structure for subwavelength terahertz waveguiding. The mode properties and their dependence on frequency, nanowire size, permittivity and chemical potential of graphene are studied in detail by using a finite element method, they are also compared with the graphene-coated circular nanowires (GCCNWs). Results showed that the ratio of the long and short axes (b/a) of the elliptical nanowire had significant influence on mode properties, they also showed that a propagation length over 200 μm and a normalized mode area of approximately 10−4~10−3 could be obtained. Increasing b/a could simultaneously achieve both long propagation length and very small full width at half maximum (FWHM) of the focal spots. When b/a = 10, a pair of focal spots about 40 nm could be obtained. Results also showed that the GCENW had a better waveguiding performance when compared with the corresponding GCCNWs. The manipulation of Terahertz (THz) waves at a subwavelength scale using graphene plasmon (GP) may lead to applications in tunable THz components, imaging, and nanophotonics.


2014 ◽  
Vol 26 (14) ◽  
pp. 1399-1402 ◽  
Author(s):  
Shanshan Li ◽  
Hao Zhang ◽  
Jinjun Bai ◽  
Weiwei Liu ◽  
Ziwei Jiang ◽  
...  

2010 ◽  
Vol 97 (13) ◽  
pp. 133502 ◽  
Author(s):  
Dongbin Tian ◽  
Huaiwu Zhang ◽  
Qiye Wen ◽  
Zhiguo Wang ◽  
Sheng Li ◽  
...  

Author(s):  
Subhashish Dolai ◽  
Massood Tabib-Azar

Our main objective in this work was to examine the possibility of non-intrusive, label-free, detection of whole Zika viruses using terahertz signals with or without a targeting/binding oligonucleotide (aptamers). We report for the first time the use of terahertz electromagnetic waves (0.75 THz – 1.1 THz) to detect Zika viruses. The Zika/aptamer complexes showed a reproducible terahertz reflection coefficient minimum at 1.064 THz while the Zika virus’s reflection minimum was at 1.073 THz. Of different substrates we examined, the polyester petri dish provided a very low loss and excellent terahertz transmission. To increase the interaction between the terahertz signal and the sample we also used polyester microbeads coated with aptamers. We then measured the terahertz reflection from the microbeads as a function of Zika concentration. The resulting terahertz Zika sensor had sensitivity of 63 Hz/Zika and minimum detectable signal of ~ 16x103 Zika. Other substrates such as Graphene on polyethylene terephthalate (PET), 50 nm-thick gold film on polycarbonate, thin (30 um-thick) glass slide and Teflon were also examined. Graphene substrate enabled direct detection of the Zika without any aptamers.


Author(s):  
Mohd Syafiq Sharip ◽  
Norazlianie Sazali ◽  
Fatin Nurwahdah Ahmad

Hydrogen (H2)-based economy development is expected to create extensive need for efficient collecting strategies of fairly high purity H2. The aim of a H2-selective membrane is to manipulate H2’s high diffusivity characteristics as well as to restrict the outcome of lower solubility. Carbon membranes offer high potential in gas separation industry due to its highly permeable and selective. Therefore, this study aims to investigate the effect of carbonization parameter, i.e., polymer concentration on the gas separation properties. Matrimid 5218 was used as a precursor for carbon tubular membrane preparation to produce high quality of carbon membrane via carbonization process. The polymer solution was coated on the surface of tubular ceramic tubes using dip-coating method. Matrimid 5218-based carbon tubular membranes were fabricated and characterized in terms of its structural morphology, chemical structure, thermal stability, and gas permeation properties by using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and pure gas permeation system, respectively. The polymer solution containing 15 wt% Matrimid 5218 shows the best formulation for the preparation of Matrimid 5218-based carbon tubular membrane. The highest H2/N2 selectivity of 401.08±2.56 was obtained for carbon membrane carbonized at 800oC with heating rate of 2oC/min.


2008 ◽  
Vol 92 (16) ◽  
pp. 161102 ◽  
Author(s):  
Markus Wächter ◽  
Michael Nagel ◽  
Heinrich Kurz

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