Monitoring of soybean biodiesel based on the one-dimensional photonic crystals comprising porous silicon

Author(s):  
Hussein A. Elsayed ◽  
Ahmed Mehaney
2010 ◽  
Vol 663-665 ◽  
pp. 725-728 ◽  
Author(s):  
Yuan Ming Huang ◽  
Qing Lan Ma ◽  
Bao Gai Zhai ◽  
Yun Gao Cai

Considered the model of the one-dimensional photonic crystals (1-D PCs) with double defects, the refractive indexes (n2’, n3’ and n2’’, n3’’) of the double defects were 2.0, 4.0 and 4.0, 2.0 respectively. With parameter n2=1.5, n3=2.5, by theoretical calculations with characteristic matrix method, the results shown that for a certain number (14 was taken) of layers of the 1-D PCs, when the double defects abutted, there was a defect band gap in the stop band gap, while when the double defects separated, there occurred two defect band gaps in the stop band gap; besides, with the separation of the two defects, the transmittance of the double defect band gaps decreased gradually. In addition, in this progress, the frequency range of the stop band gap has a little increase from 0.092 to 0.095.


2019 ◽  
Vol 560 ◽  
pp. 133-139 ◽  
Author(s):  
I.A. Lujan-Cabrera ◽  
C.F. Ramirez-Gutierrez ◽  
J.D. Castaño-Yepes ◽  
M.E. Rodriguez-Garcia

2010 ◽  
Vol 97 (11) ◽  
pp. 113106 ◽  
Author(s):  
Shahar Mor ◽  
Vicente Torres-Costa ◽  
Raúl J. Martín-Palma ◽  
I. Abdulhalim

2018 ◽  
Vol 32 (11) ◽  
pp. 1850136 ◽  
Author(s):  
J. S. Pérez-Huerta ◽  
D. Ariza-Flores ◽  
R. Castro-García ◽  
W. L. Mochán ◽  
G. P. Ortiz ◽  
...  

We report the reflectivity of one-dimensional finite and semi-infinite photonic crystals, computed through the coupling to Bloch modes (BM) and through a transfer matrix method (TMM), and their comparison to the experimental spectral line shapes of porous silicon (PS) multilayer structures. Both methods reproduce a forbidden photonic bandgap (PBG), but slowly-converging oscillations are observed in the TMM as the number of layers increases to infinity, while a smooth converged behavior is presented with BM. The experimental reflectivity spectra is in good agreement with the TMM results for multilayer structures with a small number of periods. However, for structures with large amount of periods, the measured spectral line shapes exhibit better agreement with the smooth behavior predicted by BM.


2021 ◽  
Author(s):  
Fupei Wu ◽  
Hao Zhang ◽  
Baofei Wan ◽  
Haifeng Zhang

Abstract Electromagnetic (EM) absorption is the basic characteristic of materials that plays an important role in many applications such as solar cells, EM radiation protection, and stealth technology. However, under normal circumstances, the traditional medium's absorption efficiency of EM waves is limited, but the designer can operate by adjusting the structure of the medium. In this paper, the coherent perfect absorption (CPA) is introduced in the one-dimensional (1-D) non-magnetized plasma photonic crystals. Under the premise that the selected material meets the conditions (appropriate thickness and dielectric constant), the absorption amplitude at the frequency point that meets the coherent absorption conditions is greatly improved. The results show that the forward and backward EM waves that meet the CPA conditions and propagate in PPCs can increase the absorption to 99.94% and change the phase difference of the two coherent beams to control the adjustment range of the absorption efficiency to 12.60%-99.94%. In addition, the effects of plasma and collision frequency on the absorption property, and the effects of the periodic constant of dielectric layers and plasma thickness on the frequency and amplitude of coherent absorption are also presented. It is foreseeable that the idea of tunability of light absorption in photovoltaic cells is proposed in this paper, and the application of absorbers in the field of optical switching and light modulation has been further expanded.


Optik ◽  
2021 ◽  
Vol 248 ◽  
pp. 168056
Author(s):  
Hussein A. Elsayed ◽  
Arvind Sharma ◽  
Francis Segovia-Chaves ◽  
Walied Sabra

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