scholarly journals Dual-Band Light Absorption Enhancement in Hyperbolic Rectangular Array

2019 ◽  
Vol 9 (10) ◽  
pp. 2011 ◽  
Author(s):  
Honglong Qi ◽  
Tian Sang ◽  
La Wang ◽  
Xin Yin ◽  
Jicheng Wang ◽  
...  
Keyword(s):  
Light Absorption ◽  
Effective Medium Theory ◽  
Impedance Matching ◽  
Dual Band ◽  
Absorption Enhancement ◽  
Absorption Bands ◽  
Absorption Properties ◽  
Rectangular Array ◽  
Medium Theory ◽  
Band Absorption

The effect of dual-band light absorption enhancement in a hyperbolic rectangular array (HRA) is presented. The enhanced light absorption of the HRA results from the propagating surface plasmon (PSP) resonance, and a dual-band absorption with low and flat sideband level can be realized. The impedance theory is used to evaluate the absorption properties of the HRA, and shows that the input impedances of the HRA varied abruptly around the absorption bands to meet the impedance matching. The absorption spectra of the HRA can be estimated using the effective medium theory (EMT), and its accuracy can be improved as the number of film stacks is increased. The dual-band absorptions of the HRA are very robust to the variations of the width and the number of film stack. Potential application in refractive index sensing can be achieved by utilizing the two absorption bands.

scholarly journals Optical analysis using effective medium theory and finite element method to study the enhanced light absorption in porous BaMgAl-=SUB=-10-=/SUB=-O-=SUB=-17-=/SUB=- : Eu-=SUP=-2+-=/SUP=- phosphor

2019 ◽  
Vol 61 (8) ◽  
pp. 1505
Author(s):  
Ying-Lin Liang ◽  
Liang-Jun Yin ◽  
Hao-Van Bui ◽  
Xian Jian ◽  
Guang Yang ◽  
...  
Keyword(s):  
Finite Element ◽  
Optical Properties ◽  
Light Absorption ◽  
Effective Medium Theory ◽  
Effective Medium ◽  
Absorption Enhancement ◽  
Optical Analysis ◽  
Medium Theory ◽  
Excitation Light ◽  
Element Simulation

AbstractThe main objective of this paper is to reveal the mechanism of enhanced excitation light absorption in nano-pores structure BaMgAl_10O_17:Eu^2+ (BAM) phosphor by optical analysis. The optical refractive index of the BAM was calculated from the reflectance spectra by Kramers–Kronig dispersion relation. And based on the effective medium theory, the anisotropic optical properties of porous BAM layer and its relations of absorption enhancement with porosity and thickness were investigated. A finite element simulation model was used for study the influence of pores size on optical properties. All the numerically evaluated results were match the experimental data.

scholarly journals Numerical Study of Angle-Insensitive and Tunable Dual-Band THz Absorber Using Periodic Cross-Shaped Graphene Arrays

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2063 ◽  
Author(s):  
Tian Sang ◽  
Jian Gao ◽  
La Wang ◽  
Honglong Qi ◽  
Xin Yin ◽  
...  
Keyword(s):  
Transverse Electric ◽  
Numerical Study ◽  
Transverse Magnetic ◽  
Dual Band ◽  
Absorption Enhancement ◽  
Cavity Model ◽  
Absorption Bands ◽  
Fabry Perot ◽  
Band Absorption ◽  
The Cross

A dual-band terahertz (THz) absorber using the periodic cross-shaped graphene arrays is presented. It is shown that the dual-band light absorption enhancement of graphene results from the edge graphene plasmon (EGP) resonance, and the locations of the two absorption peaks can be precisely estimated by using the Fabry-Pérot (F-P) cavity model. Slight residual reflection remains at the two absorption peaks because the input impedance of the cross-arm cannot be perfectly matched with the free space impedance. In addition, the locations of the two absorption bands can be simultaneously tuned by changing the Fermi level of graphene, and they can be independently tuned by changing the width or the length of the cross-arm of graphene. Excellent angle-insensitivity dual-band absorption enhancement of graphene can be maintained for both the transverse electric (TE) and transverse magnetic (TM) polarizations.

scholarly journals Investigation on the Optical Dual-band Absorption Enhancement for Graphene Photodetector

2021 ◽  
pp. 104747
Author(s):  
Haixia Liu ◽  
Shashi Zhang ◽  
Hao Ding ◽  
Wei Sun ◽  
Lichen Sun
Keyword(s):  
Dual Band ◽  
Absorption Enhancement ◽  
Band Absorption

Multispectral Plasmon of Anisotropic Core-shell Gold Nanorods@SiO2: Dual-band Absorption Enhancement with Coupling Dye Molecules

2018 ◽  
Vol 34 (5) ◽  
pp. 772-780 ◽  
Author(s):  
Yuping Che ◽  
Yang Wang ◽  
Tingting You ◽  
Huaiqiu Chang ◽  
Penggang Yin ◽  
...  
Keyword(s):  
Gold Nanorods ◽  
Dual Band ◽  
Absorption Enhancement ◽  
Core Shell ◽  
Dye Molecules ◽  
Band Absorption

Dual-band metamaterial absorber with stable absorption performance based on fractal structure

2021 ◽  
Author(s):  
Shuguang Fang ◽  
Lianwen Deng ◽  
Pin Zhang ◽  
Lei-Lei Qiu ◽  
Haipeng Xie ◽  
...  
Keyword(s):  
Fractal Structure ◽  
Low Cost ◽  
Impedance Matching ◽  
Metamaterial Absorber ◽  
Dual Band ◽  
Fractal Structures ◽  
Absorption Bands ◽  
Electromagnetic Resonance ◽  
Absorption Performance ◽  
Multi Band

Abstract In this paper, two kinds of dual-band metamaterial absorbers (MMAs) with stable absorption performance based on fractal structures are proposed. As the key feature, with the increase in fractal order, the fractal MMAs can reduce the weight while keeping the absorption performance. The multi-band absorption property is analyzed by multiple L-C resonances generated by the fractal structure. By virtue of good impedance matching characteristics and the synergy of the circuit and electromagnetic resonance, effective and stable microwave absorption is readily achieved. Finally, two prototypes are fabricated for demonstration, and the measurement result is consistent well with the simulation one. As expected, the proposed fractal MMAs have the advantage of low-cost, light-weight, and dual-effective absorption bands, and have great potential in the application of multi-band radar stealth.

scholarly journals Symmetry-broken square silicon patches for ultra-narrowband light absorption

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xin Yin ◽  
Tian Sang ◽  
Honglong Qi ◽  
Guoqing Li ◽  
Xun Wang ◽  
...  
Keyword(s):  
Light Absorption ◽  
Impedance Matching ◽  
Resonance Mode ◽  
Absorption Enhancement ◽  
Narrow Slit ◽  
Cavity Model ◽  
Fabry Perot ◽  
Wave Patterns ◽  
Refractive Index Sensors ◽  
Absorption Features

AbstractThe effect of ultra-narrowband light absorption enhancement is presented by using metamaterials with symmetry-broken square silicon patches (SSPs). The symmetry of the SSP can be broken by introducing a narrow slit deviating from its center. By breaking the symmetry of the SSPs, slit resonance mode with standing wave patterns can be excited, and the locations of the absorption peaks can be well estimated by using the Fabry-Pérot (F-P) cavity model. Although there is no excitation of surface plasmon resonance, ultra-narrowband light absorption can be achieved by minimizing the reflectance through perfect impedance matching and simultaneously eliminating the transmittance by the metallic substrate. Good ultra-narrowband absorption features can be maintained as the parameters of the buffer layer and the SSPs are altered. When this type of symmetry-broken SSPs-based metamaterial is used in refractive-index sensors, it shows excellent sensing properties due to its stable ultra-narrowband absorption enhancement.

Nanofoam Porosity Measured by Infrared Spectroscopy and Refractive Index

1996 ◽  
Vol 431 ◽  
Author(s):  
M. I. Sanchez ◽  
J. L. Hedrick ◽  
T. P. Russell
Keyword(s):  
Refractive Index ◽  
Infrared Spectroscopy ◽  
Effective Medium Theory ◽  
Gradient Methods ◽  
Quantitative Agreement ◽  
Spherical Particles ◽  
Void Content ◽  
Absorption Bands ◽  
Medium Theory ◽  
Poly Propylene

AbstractInfrared spectroscopy and optical waveguide were used to determine the porosity of polymer nanofoams produced from block copolymers of an aromatic polyimide endcapped with either poly(propylene oxide) or poly(a-methylstyrene). The infrared absorption bands and film thickness were compared to those of the neat homopolymer to yield an accurate measure of the void content. The porosity was also determined by measuring the refractive index and using the Maxwell-Garnett effective medium theory for spherical particles. Both techniques are in quantitative agreement with density gradient methods.

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