The optical scalar equations in the presence of a refractive medium

1983 ◽  
Vol 265 ◽  
pp. 451 ◽  
Author(s):  
T. W. Noonan
1986 ◽  
Vol 64 (2) ◽  
pp. 160-164
Author(s):  
Charles C. Dyer

The theory of static gravitatonal lenses is discussed using the optical scalar formalism and the ray-bending approximation to this formalism. The advantages of each approach are discussed, with particular emphasis on the use of the bending approximation for discretely observable lenses, say multiply imaged quasars, and the optical scalar equations for cumulative effects of inhomogeneities for distant objects in the universe.The effect of a locally lumpy distribution on the past null cone of a typical observer is discussed. This is of particular interest in deciding the limits to which one can hope to do cosmology through the use of optical and other telescopes. The optical-scalar-equation driving terms can be replaced by appropriately defined mean driving terms for subsets of observable objects, and coupled with corresponding probabilities, these calculations can yield estimates of the "thickness" of the observer's past null cone as a function of the red shift. This imposes a limit on the use of standard observations in determining the structure of the universe, simply owing to the "fuzzy" structure of the perceived past null cone.


1997 ◽  
Vol 12 (27) ◽  
pp. 4831-4835 ◽  
Author(s):  
K. S. Virbhadra

We show that the well-known most general static and spherically symmetric exact solution to the Einstein-massless scalar equations given by Wyman is the same as one found by Janis, Newman and Winicour several years ago. We obtain the energy associated with this space–time and find that the total energy for the case of the purely scalar field is zero.


2021 ◽  
Vol 129 (4) ◽  
pp. 044502
Author(s):  
Rui Zhang ◽  
Rahul Mhaskar ◽  
Ken Smith ◽  
Easswar Balasubramaniam ◽  
Mark Prouty
Keyword(s):  

2014 ◽  
Vol 571-572 ◽  
pp. 915-919
Author(s):  
Xiao Xue Xu ◽  
Zhong Yin Xiao ◽  
Quan Wen Ma ◽  
Xiao Long Ma ◽  
De Jun Liu ◽  
...  

According to Maxwell equations and constitutive relations in chiral medium, the dispersion characteristic of the symmetric slab waveguide with chiral negative refractive medium is studied. The dispersion equations expressed in the normalized parameter are deduced in the slab waveguide. The numerical results show that the chiral parameter has great influence on the dispersion characteristic of slab waveguide. When the relative chiral parameter is about 0.0477, the zero order mode of left-handed polarized wave disappears. While it is greater than 1, the core becomes chiral negative refractive medium and the zero order mode disappears. In addition, compared with the general chiral waveguide, the tendency of dispersion curves in slab waveguide with chiral negative refractive medium is also analyzed.


2013 ◽  
Vol 22 (06) ◽  
pp. 1360019
Author(s):  
DAMON BLANCHETTE ◽  
EMMANUEL AGU

Spectral rendering, or the synthesis of images by taking into account the constituent wavelengths of white light, enables the rendering of iridescent colors caused by phenomena such as dispersion, diffraction, interference and scattering. Caustics, the focusing and defocusing of light through a refractive medium, can be interpreted as a special case of dispersion where all the wavelengths travel along the same paths. In this paper we extend Adaptive Caustic Mapping (ACM), a previously proposed caustics mapping algorithm, to handle physically-based dispersion. Because ACM can display caustics in real-time, it is amenable to extension to handle the more general case of dispersion. We also present a novel algorithm for filling in the gaps that occur due to discrete sampling of the spectrum. Our proposed method runs in screen-space, and is fast enough to display plausible dispersion phenomena at real-time and interactive frame rates.


2014 ◽  
Vol 1671 ◽  
Author(s):  
Peiqing Yu ◽  
Jean-Philippe Blondeau ◽  
Caroline Andreazza ◽  
Esidor Ntsoenzok ◽  
Julien Roussel ◽  
...  

ABSTRACTThe efficiency of thin-film solar cells using a-Si:H is limited by the decrease in a-Si:H layer optical path length and its poor light absorption at red and NIR wavelengths. Metal NP such as Au have been shown to increase the absorption in the active material and then cell performances, by exhibiting localized surface plasmon (LSP) resonances. Our work’s goal is to understand NP influence in such cells, to perform an optimal structure by increasing the amount of light absorbed within the cell using NP scattering and luminescence. Modeling based on Mie theory is first carried out using bulk Palik data for Au spheres with various diameters and refractive medium indexes. Using modeling parameters, Au layers were deposited on glass and SnO2 substrates respectively by thermal evaporation in vacuum and sputtering, followed by thermal annealing (200 ∼ 500°C) in order to promote the NP growth. MEB pictures show quasispherical Au NP shape with a mean size of 150nm. This diameter range switches extinction of NP in scattering regime. Annealing temperature (T) strongly affects the NP morphology. Surface coverage decreases and sphericity appears to increase with T. UV-Visible spectroscopy displays distinct LSP resonances around 600nm after annealing with a red shift while T increases.


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