Influence of structural symmetry on resonant property and optical sensitivity in terahertz metamaterials

2015 ◽  
Vol 336 ◽  
pp. 106-109 ◽  
Author(s):  
Chenyu Li ◽  
Qingli Zhou ◽  
Ani Wu ◽  
Yulei Shi ◽  
Jianfeng Liu ◽  
...  
2008 ◽  
Vol 59 (10) ◽  
pp. 1169-1171 ◽  
Author(s):  
Zoltan Borsos ◽  
Viorel-Puiu Paun ◽  
Irinel Casian Botez ◽  
Cristina-Maria Stoica ◽  
Petrica Vizureanu ◽  
...  

In this paper, the explicit connection between the high structural symmetry of the carbon nanotubes and the electrical properties is studied. An interesting path effect on the transport properties will be proved. For a bidimensional lattice, the conductivity sx depends on the structural form, which determines the shape of electron path, respectively it is direct proportional to the fractal dimension of this path.


Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 123
Author(s):  
Zhong Lijing ◽  
Roman A. Zakoldaev ◽  
Maksim M. Sergeev ◽  
Andrey B. Petrov ◽  
Vadim P. Veiko ◽  
...  

Laser direct writing technique in glass is a powerful tool for various waveguides’ fabrication that highly develop the element base for designing photonic devices. We apply this technique to fabricate waveguides in porous glass (PG). Nanoporous optical materials for the inscription can elevate the sensing ability of such waveguides to higher standards. The waveguides were fabricated by a single-scan approach with femtosecond laser pulses in the densification mode, which resulted in the formation of a core and cladding. Experimental studies revealed three types of waveguides and quantified the refractive index contrast (up to Δn = 1.2·10−2) accompanied with ~1.2 dB/cm insertion losses. The waveguides demonstrated the sensitivity to small objects captured by the nanoporous framework. We noticed that the deposited ethanol molecules (3 µL) on the PG surface influence the waveguide optical properties indicating the penetration of the molecule to its cladding. Continuous monitoring of the output near field intensity distribution allowed us to determine the response time (6 s) of the waveguide buried at 400 µm below the glass surface. We found that the minimum distinguishable change of the refractive index contrast is 2 × 10−4. The results obtained pave the way to consider the waveguides inscribed into PG as primary transducers for sensor applications.


2009 ◽  
Vol 21 (45) ◽  
pp. 456007 ◽  
Author(s):  
H Martinho ◽  
C Rettori ◽  
G M Dalpian ◽  
J L F da Silva ◽  
Z Fisk ◽  
...  

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Wen-ao Cao ◽  
Donghao Yang ◽  
Huafeng Ding

The umbrella linkage is one of the most classical deployable mechanisms. This paper concentrates on topological structural design of a family of umbrella-shaped deployable mechanisms based on new two-layer and two-loop spatial linkage units. First, deployable units are developed systematically from two-layer and two-loop linkage with four revolute pair (4R) coupling chains. Then, mobile connection modes of the deployable units are established based on the conditions of one degree-of-freedom (DOF) and structural symmetry. Finally, umbrella-shaped deployable mechanisms are constructed based on the developed deployable units and the established mobile connection modes. Like umbrellas, the designed deployable mechanisms can be actuated in a simple and reliable way, and those mechanisms have good potential applications in the fields of architecture, manufacturing, space exploration, and recreation.


2014 ◽  
Vol 369 (1636) ◽  
pp. 20130039 ◽  
Author(s):  
Eva Landgren ◽  
Kerstin Fritsches ◽  
Richard Brill ◽  
Eric Warrant

Escolar ( Lepidocybium flavobrunneum , family Gempylidae) are large and darkly coloured deep-sea predatory fish found in the cold depths (more than 200 m) during the day and in warm surface waters at night. They have large eyes and an overall low density of retinal ganglion cells that endow them with a very high optical sensitivity. Escolar have banked retinae comprising six to eight layers of rods to increase the optical path length for maximal absorption of the incoming light. Their retinae possess two main areae of higher ganglion cell density, one in the ventral retina viewing the dorsal world above (with a moderate acuity of 4.6 cycles deg −1 ), and the second in the temporal retina viewing the frontal world ahead. Electrophysiological recordings of the flicker fusion frequency (FFF) in isolated retinas indicate that escolar have slow vision, with maximal FFF at the highest light levels and temperatures (around 9 Hz at 23°C) which fall to 1–2 Hz in dim light or cooler temperatures. Our results suggest that escolar are slowly moving sit-and-wait predators. In dim, warm surface waters at night, their slow vision, moderate dorsal resolution and highly sensitive eyes may allow them to surprise prey from below that are silhouetted in the downwelling light.


2010 ◽  
Vol 105 (24) ◽  
Author(s):  
Hou-Tong Chen ◽  
Hao Yang ◽  
Ranjan Singh ◽  
John F. O’Hara ◽  
Abul K. Azad ◽  
...  

1992 ◽  
Vol 55 ◽  
pp. 129
Author(s):  
J.G. Sivak ◽  
D.D. Stuart ◽  
K.L. Herbert ◽  
J.A. Van Oostrom
Keyword(s):  

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