scholarly journals Coherent backscattering of light by an anisotropic biological network

2018 ◽  
Vol 9 (1) ◽  
pp. 20180050 ◽  
Author(s):  
Gianni Jacucci ◽  
Olimpia D. Onelli ◽  
Antonio De Luca ◽  
Jacopo Bertolotti ◽  
Riccardo Sapienza ◽  
...  
Keyword(s):  
Refractive Index ◽  
Spatial Distribution ◽  
Optical Anisotropy ◽  
Experimental Approach ◽  
Biological Network ◽  
Random Medium ◽  
Coherent Backscattering ◽  
Scattering Efficiency ◽  
Synthetic Materials ◽  
Scattering Strength

The scattering strength of a random medium relies on the geometry and spatial distribution of its components as well as on their refractive index. Anisotropy can, therefore, play a major role in the optimization of the scattering efficiency in both biological and synthetic materials. In this study, we show that, by exploiting the coherent backscattering phenomenon, it is possible to characterize the optical anisotropy inCyphochilusbeetle scales without the need to change their orientation or their thickness. For this reason, such a static and easily accessible experimental approach is particularly suitable for the study of biological specimens. Moreover, estimation of the anisotropy inCyphochilusbeetle scales might provide inspiration for improving the scattering strength of artificial white materials.

scholarly journals Coherent backscattering effect on wave dynamics in a random medium

2000 ◽  
Vol 52 (5) ◽  
pp. 518-524 ◽  
Author(s):  
H Schomerus ◽  
K. J. H. van Bemmel ◽  
C. W. J Beenakker
Keyword(s):  
Random Medium ◽  
Coherent Backscattering ◽  
Wave Dynamics

Optical properties of a liquid crystal with small ordinary and extraordinary refractive indices and small optical anisotropy

2014 ◽  
Vol 22 (3) ◽  
Author(s):  
J. Kędzierski ◽  
K. Garbat ◽  
Z. Raszewski ◽  
M. Kojdecki ◽  
K. Kowiorski ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Liquid Crystal ◽  
Optical Anisotropy ◽  
Order Parameter ◽  
Orientational Order ◽  
Refractive Indices ◽  
Orientational Order Parameter ◽  
Unknown Density ◽  
Abbe Refractometer

AbstractOptical properties of a nematic liquid crystal with small refractive index and small birefringence were studied. The ordinary and extraordinary refractive indices and birefringence were measured as functions of temperature by using an Abbe refractometer and wedge nematic cells. From values of these indices the nematic orientational order parameter was calculated by using several methods and corresponding mathematical models. Kuczyński et al. method was found to be suitable for determining the order parameter also for materials featuring small ordinary refractive index, with unknown density.

scholarly journals Combined Modeling of the Optical Anisotropy of Porous Thin Films

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 517 ◽  
Author(s):  
F. V. Grigoriev ◽  
V. B. Sulimov ◽  
A.V. Tikhonravov
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Anisotropy ◽  
Effective Medium Theory ◽  
Deposition Process ◽  
Dynamics Simulation ◽  
Porous Thin Films ◽  
Simulation Results ◽  
The Difference ◽  
Main Components

In this article, a combined approach for studying the optical anisotropy of porous thin films obtained by the glancing angle deposition is presented. This approach combines modeling on the atomistic and continuum levels. First, thin films clusters are obtained using the full-atomistic molecular dynamics simulation of the deposition process. Then, these clusters are represented as a medium with anisotropic pores, the shapes parameters of which are determined using the Monte Carlo based method. The difference in the main components of the refractive index is calculated in the framework of the anisotropic Bruggeman effective medium theory. The presented approach is tested and validated by comparing the analytical and simulation results for the model problems, and then is applied to silicon dioxide thin films. It is found that the maximum difference between the main components of the refractive index is 0.035 in a film deposited at an angle of 80°. The simulation results agree with the experimental data reported in the literature.

scholarly journals Radio Astronomical Scintillation in the Solar Wind Plasma: Imaging Interplanetary Disturbances

2002 ◽  
Vol 199 ◽  
pp. 426-429 ◽  
Author(s):  
P.K. Manoharan ◽  
M. Pick ◽  
Lasco Consortium
Keyword(s):  
Solar Wind ◽  
Refractive Index ◽  
Random Medium ◽  
Solar Wind Plasma ◽  
Radio Sources ◽  
The Sun ◽  
Radio Waves ◽  
Paper Briefly ◽  
Plasma Imaging ◽  
Salient Features

When radio waves propagate through a irregular medium, scattering by the random refractive index inhomogeneities can lead to a wide variety of phenomena, which include intensity scintillation. The observed scattering can be interpreted to gain information about the random medium and such inversion studies are valuable when the accessibility of the medium becomes difficult. This paper briefly describes the intensity scintillation of celestial radio sources caused by the turbulence in the solar wind and summarizes the salient features of the method employed in mapping the structure of disturbances leaving the Sun out to ∼1 AU.

scholarly journals Spectral Radiative Properties of a Liquid n-Octane Droplet in the Midinfrared Region

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Liang Zhao ◽  
Chaoyu Jing ◽  
Yu Jin ◽  
Jiangping Chen ◽  
Ke Yin ◽  
...  
Keyword(s):  
Refractive Index ◽  
Wavelength Range ◽  
Optical Constants ◽  
Absorption Efficiency ◽  
Efficiency Factor ◽  
Radiative Properties ◽  
Droplet Radius ◽  
Scattering Efficiency ◽  
Scattering Coefficients ◽  
Increasing Temperature

The optical constants of a liquid hydrocarbon such as liquid n-octane are basic material properties that may be used to evaluate their thermal radiation transfer capabilities. In this study, the ellipsometry method was used to measure the optical constants of liquid n-octane in the midinfrared wavelength range of 2.0–16.0 μm at temperatures of 20, 50, and 80°C. Experimental analyses indicate the significant effect of temperature on the refractive index, although it has little effect on the absorption index. With increasing temperature, the refractive index shows a linear decrease, and reduced density leads to weaker absorption intensities. The radiative properties of n-octane droplets, including the absorption and scattering efficiency factors of single droplets with droplet radii r = 10, 20, 50, and 100 μm and the absorption and scattering coefficients in a droplets-air system of droplet volume fractions fv = 2%, 3%, and 4%, were calculated using Mie theory. The numerical results indicate that, with increasing temperature, the absorption efficiency factor slightly decreases, and the variation trend of the scattering efficiency factor is more complicated. With increasing droplet radius, the absorption efficiency factor increases within the studied wavelength range, except for certain absorption peaks, but the scattering efficiency factor tends to decrease. While the absorption is greater, the scattering is weaker for a given droplet radius. With an increasing volume fraction of n-octane droplets, the absorption and scattering coefficients increase linearly within the studied wavelength range.

In-Plane Optical Anisotropy of GaN Refractive Index in Visible Light Region

2009 ◽  
Vol 21 (14) ◽  
pp. 966-968 ◽  
Author(s):  
R. Dylewicz ◽  
S. Patela ◽  
R. A. Hogg ◽  
P. W. Fry ◽  
P. J. Parbrook ◽  
...  
Keyword(s):  
Refractive Index ◽  
Visible Light ◽  
Optical Anisotropy ◽  
Visible Light Region ◽  
Light Region

scholarly journals Dynamics of random laser and coherent backscattering of light from ZnO amplifying random medium

2007 ◽  
Vol 91 (24) ◽  
pp. 241110 ◽  
Author(s):  
T. Sun ◽  
Z. R. Qiu ◽  
H. M. Su ◽  
X. D. Zhang ◽  
Z. Q. Zhang ◽  
...  
Keyword(s):  
Random Medium ◽  
Random Laser ◽  
Coherent Backscattering
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