35 research outputs found
Replacement of ensemble averaging by the use of a broadband source in scattering of light from a one-dimensional randomly rough interface between two dielectric media
By the use of phase perturbation theory we show that if a single realization
of a one-dimensional randomly rough interface between two dielectric media is
illuminated at normal incidence from either medium by a broadband Gaussian
beam, it produces a scattered field whose differential reflection coefficient
closely matches the result produced by averaging the differential reflection
coefficient produced by a monochromatic incident beam over the ensemble of
realizations of the interface profile function.Comment: 10 pages, 7 figure
The Scattering of Electromagnetic Waves from Two-Dimensional Randomly Rough Perfectly Conducting Surfaces: The Full Angular Intensity Distribution
By a computer simulation approach we study the scattering of - or
-polarized light from a two-dimensional, randomly rough, perfectly
conducting surface. The pair of coupled inhomogeneous integral equations for
two independent tangential components of the magnetic field on the surface are
converted into matrix equations by the method of moments, which are then solved
by the biconjugate gradient stabilized method. The solutions are used to
calculate the mean differential reflection coefficient for given angles of
incidence and specified polarizations of the incident and scattered fields. The
full angular distribution of the intensity of the scattered light is obtained
for strongly randomly rough surfaces by a rigorous computer simulation
approach.Comment: 15 pages (RevTeX
The Angular Intensity Correlation Functions and for the Scattering of S-Polarized Light from a One-Dimensional Randomly Rough Dielectric Surface
We calculate the short-range contributions and to the
angular intensity correlation function for the scattering of s-polarized light
from a one-dimensional random interface between two dielectric media. The
calculations are carried out on the basis of a new approach that separates out
explicitly the contributions a nd to the angular intensity
correlation function. The contribution displays peaks associated with
the memory effect and the reciprocal memory effect. In the case of a
dielectric-dielectric interface, which does not support surface electromagnetic
surface waves, these peaks arise from the co herent interference of
multiply-scattered lateral waves supported by the in terface. The contribution
is a structureless function of its arguments.Comment: LaTeX, 14 pages including 5 figures. To appear SPIE publicatio
Numerical studies of the scattering of light from a two-dimensional randomly rough interface between two dielectric media
The scattering of polarized light incident from one dielectric medium on its
two-dimensional randomly rough interface with a second dielectric medium is
studied. A reduced Rayleigh equation for the scattering amplitudes is derived
for the case where p- or s-polarized light is incident on this interface, with
no assumptions being made regarding the dielectric functions of the media.
Rigorous, purely numerical, nonperturbative solutions of this equation are
obtained. They are used to calculate the reflectivity and reflectance of the
interface, the mean differential reflection coefficient, and the full angular
distribution of the intensity of the scattered light. These results are
obtained for both the case where the medium of incidence is the optically less
dense medium, and in the case where it is the optically more dense medium.
Optical analogues of the Yoneda peaks observed in the scattering of x-rays from
metal surfaces are present in the results obtained in the latter case. Brewster
scattering angles for diffuse scattering are investigated, reminiscent of the
Brewster angle for flat-interface reflection, but strongly dependent on the
angle of incidence. When the contribution from the transmitted field is added
to that from the scattered field it is found that the results of these
calculations satisfy unitarity with an error smaller than .Comment: 25 pages, 14 figure
The Scattering of Electromagnetic Waves from Two-Dimensional Randomly Rough Penetrable Surfaces
An accurate and efficient numerical simulation approach to electromagnetic
wave scattering from two-dimensional, randomly rough, penetrable surfaces is
presented. The use of the M\"uller equations and an impedance boundary
condition for a two-dimensional rough surface yields a pair of coupled
two-dimensional integral equations for the sources on the surface in terms of
which the scattered field is expressed through the Franz formulas. By this
approach, we calculate the full angular intensity distribution of the scattered
field that is due to a finite incident beam of -polarized light. We
specifically check the energy conservation (unitarity) of our simulations (for
the non-absorbing case). Only after a detailed numerical treatment of {\em
both} diagonal and close-to-diagonal matrix elements is the unitarity condition
found to be well-satisfied for the non-absorbing case (), a
result that testifies to the accuracy of our approach.Comment: Revtex, 4 pages, 2 figure
Light scattering from an amplifying medium bounded by a randomly rough surface: A numerical study
We study by numerical simulations the scattering of -polarized light from
a rough dielectric film deposited on the planar surface of a semi-infinite
perfect conductor. The dielectric film is allowed to be either active or
passive, situations that we model by assigning negative and positive values,
respectively, to the imaginary part of the dielectric constant of
the film. We study the reflectance and the total scattered energy
for the system as functions of both and the angle of
incidence of the light. Furthermore, the positions and widths of the enhanced
backscattering and satellite peaks are discussed. It is found that these peaks
become narrower and higher when the amplification of the system is increased,
and that their widths scale linearly with . The positions of the
backscattering peaks are found to be independent of , while we find
a weak dependence on this quantity in the positions of the satellite peaks.Comment: Revtex, 9 pages, 9 figure
Waves in gradient metamaterials
This book opens a new avenue to an engendering field of applied physics, located at the “crossing” of modern photonics, electromagnetics, acoustics and material science. It also highlights the concept of “non-locality”, which proves to be not a special feature of quantum phenomena, but is shown to have an important counterpart in classical physics and its engineering applications too. Furthermore, it visualizes the physical results by means of simple analytical presentations, reduced sometimes to the elementary functions