scholarly journals One-way extraordinary optical transmission with dielectric/perforated metal/antiferromagnetic structure in the terahertz range

2016 ◽  
Vol 94 (8) ◽  
pp. 751-757
Author(s):  
Xiang guang Wang ◽  
Qiang Zhang ◽  
Shu fang Fu ◽  
Yu ling Song ◽  
Xuan zhang Wang ◽  
...  
Keyword(s):  
Optical Transmission ◽  
Effective Medium Theory ◽  
Structural Characteristics ◽  
Dielectric Materials ◽  
Wide Frequency Range ◽  
Terahertz Range ◽  
Frequency Range ◽  
Medium Theory ◽  
Optical Isolators ◽  
The One

The one-way optical effect in a dielectric/perforated metal/antiferromagnetic (DPMA) sandwich structure in the terahertz range is studied. Theoretical modeling, which is based on the effective medium theory and the transmission matrix method, is conducted. The simulation results show that the one-way effect occurs within a wide frequency range and for various incident angles with a fixed external magnetic field. In addition, this behavior is examined for various DPMA structural characteristics, such as different dielectric materials, film thicknesses, and perforated metal hole sizes and spacings. The developed sandwich structures can aid the design of subminiature optical isolators for application in the terahertz range.

Nanostructured Broad Band Infrared Absorber

2011 ◽  
Vol 1303 ◽  
Author(s):  
Timothy D. Corrigan ◽  
Dong Hun Park ◽  
Dennis Drew ◽  
Ray Phaneuf
Keyword(s):  
Effective Medium Theory ◽  
Scattered Light ◽  
Broad Band ◽  
Black Body ◽  
Index Of Refraction ◽  
Frequency Range ◽  
Multilayer Material ◽  
Medium Theory ◽  
Source Type ◽  
Broad Band Absorber

ABSTRACTWe describe a near perfect broad band absorber based on a laterally nanostructured multilayer material. We present calculations of the structure that demonstrates over 99% absorption of the 500 K black body spectrum. We also show the ability to manufacture an anti-reflective layer using a nanostructured metamaterial which allows us to tailor the index of refraction using effective medium theory. The absorber can be adapted for use in any frequency range and any source type. These materials may have applications in energy harvesting and scattered light control.

Dielectric Properties of Glass Capillary Arrays

1998 ◽  
Vol 511 ◽  
Author(s):  
T. E. Huber ◽  
Leo Silber ◽  
Frank Boccuzzi
Keyword(s):  
Dielectric Constant ◽  
Effective Medium Theory ◽  
Far Infrared ◽  
Soda Lime ◽  
Index Of Refraction ◽  
Soda Lime Glass ◽  
Frequency Range ◽  
Glass Capillary ◽  
Medium Theory ◽  
X Band

ABSTRACTGlass Capillary Arrays (GCA) are low density columnar monolithic structures made of soda-lime glass. This structure, in which 76% of volume between the columns, the channels, is void, also has a greatly reduced dielectric constant in comparison with bulk glass. We have measured the index of refraction and absorption of samples of GCA's in the X-band, 8 × 109 Hz to 1.2×1010 Hz, for various orientations of the channels with respect to the polarization. For channels perpendicular to the polarization direction we have measured an index of refraction of 1.15. In comparison the index of refraction of (bulk) soda-lime glass is 2.6. We also examined the absorption in the far-infrared (FIR) frequency range between 6×1011 Hz and 6×1012 Hz. In this frequency range we obtain a k2 dependence due to losses in the glass matrix at higher frequencies. The results of the X-band and FIR results are interpreted in terms of an effective medium theory of the real and imaginary part of the dielectric constant of the composite.

Electromagnetic Wave Absorption Behavior of NiZn-Ferrite Prepared via Hydrothermal Method

2005 ◽  
Vol 480-481 ◽  
pp. 595-602 ◽  
Author(s):  
Cheng-Hsiung Peng ◽  
Hong-Wen Wang ◽  
Shih-Wei Kan ◽  
San-Yuan Chen
Keyword(s):  
Electromagnetic Wave ◽  
Hydrothermal Method ◽  
Imaginary Part ◽  
Reflection Loss ◽  
Effective Medium Theory ◽  
Frequency Range ◽  
Medium Theory ◽  
Electromagnetic Wave Absorption ◽  
The Real ◽  
Effect Of Particle Size

Ni0.5Zn0.5Fe2O4 ferrite powders were synthesized by a hydrothermal method. The nanoparticles of these materials were mixed with a thermal-plastic polyurethane (TPU)polymer in order to form a suitable composite for electromagnetic wave absorber in a frequency range from 2.0 to 15.0 GHz. The effect of particle size on the reflection loss was investigated by comparing nanosized and microsized powders. The reflection loss as a function of frequency ( f ), thickness of the absorber(d), the real and imaginary part of permittivity (ε’ /ε”) and the real and imaginary part of permeability (μ’/μ”) were obtained by calculation using the Bruggeman effective medium theory. The effect of Co2+, Cu2+, and Mg2+ on the reflection loss was also studied.

Modelling damping in piezoceramics: A comparative study

2021 ◽  
Vol 88 (5) ◽  
pp. 294-302
Author(s):  
Nadine Feldmann ◽  
Veronika Schulze ◽  
Leander Claes ◽  
Benjamin Jurgelucks ◽  
Lars Meihost ◽  
...  
Keyword(s):  
Transversely Isotropic ◽  
Wide Frequency Range ◽  
Frequency Range ◽  
Zener Model ◽  
Simulation Tools ◽  
Frequency Independent ◽  
Limited Frequency ◽  
The One ◽  
Damping Model ◽  
Best Fit

Abstract The progress in numerical methods and simulation tools promotes the use of inverse problems in material characterisation problems. A newly developed procedure can be used to identify the behaviour of piezoceramic discs over a wide frequency range using a single specimen via fitting simulated and measured impedances by optimising the underlying material parameters. Since there is no generally accepted damping model for piezoelectric ceramics, several mechanical damping models are examined for the material identification. Three models have been chosen and their ability to replicate the measured impedances is evaluated. On the one hand, the common Rayleigh model is considered as a reference. On the other hand, a Zener model and a model using complex constants are extended to model the transversely isotropic material. As the Rayleigh model is only valid for a limited frequency range, it fails to model the broadband behaviour of the material. The model using complex constants leads to the best fit over a wide frequency range while at the same time only adding three additional parameters for modelling damping. Thus, damping can be assumed approximately frequency-independent in piezoceramics.

Effective medium theory of the one-dimensional resonance phononic crystal

2008 ◽  
Vol 20 (5) ◽  
pp. 055209 ◽  
Author(s):  
Zhi Guo Wang ◽  
Sam Hyeon Lee ◽  
Chul Koo Kim ◽  
Choon Mahn Park ◽  
Kyun Nahm ◽  
...  
Keyword(s):  
Effective Medium Theory ◽  
Phononic Crystal ◽  
Effective Medium ◽  
Medium Theory ◽  
One Dimensional ◽  
The One ◽  
Dimensional Resonance
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