1,648 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
Numerical simulation of electromagnetic wave scattering from planar dielectric films deposited on rough perfectly conducting substrates
Electromagnetic wave scattering from planar dielectric films deposited on
one-dimensional, randomly rough, perfectly conducting substrates is studied by
numerical simulations for both p- and s-polarization. The reduced Rayleigh
equation, which is the integral equation satisfied by the scattering amplitude
after eliminating the fields inside the film, is the starting point for the
simulation. This equation is solved numerically by considering a random surface
of finite length, and by introducing wave number cut-offs in the evanescent
part of the spectrum. Upon discretization, a system of linear equations is
obtained, and by solving this matrix system for an ensemble of surface
realizations, the contribution to the mean differential reflection coefficient
from the incoherently scattered field, (\nu=p,s), is obtained nonperturbatively. It is demonstrated
that when the scattering geometry supports at least two guided waves,
, has, in addition to the well known
enhanced backscattering peak, well-defined satellite peaks in agreement with
theory, for most of the parameters considered.Comment: 11 pages and 11 figure
Random Surfaces that Suppress Single Scattering
We present a method for generating numerically a one-dimensional random
surface, defined by the equation x_3 = \zx, that suppresses single-scattering
processes in the scattering of light from it within a specified range of
scattering angles. Rigorous numerical calculations of the scattering of light
from surfaces generated by this approach show that the single-scattering
contribution to the mean scattered intensity is indeed suppressed within that
range of angles.Comment: 3 pagers (Latex), 3 figure
Local Polariton States in Polar Crystals with Impurities
We show that an impurity embedded in an ionic crystal can give rise to a
novel kind of local states. These states exist within a polariton gap of a
material and are a mix of excitations of the crystal, such as phonons or
excitons, and the transverse electromagnetic field. The electromagnetic
component of the states along with the corresponding excitations of the
material are localized in the vicinity of an impurity.Comment: 9 pages, RevTe
Beer's law in semiconductor quantum dots
The propagation of a coherent optical linear wave in an ensemble of
semiconductor quantum dots is considered. It is shown that a distribution of
transition dipole moments of the quantum dots changes significantly the
polarization and Beer's absorption length of the ensemble of quantum dots.
Explicit analytical expressions for these quantities are presented
On Debye temperature anomaly observed in Ge-Se-Ag glasses
Anomalous Values of Debye temperature have been obtained from Lamb Mossbauer
factor measurements of Ge-Se-Ag glasses. We show that this anomaly may arise
due to the presence of anharmonic potential at the high spin ferrous site. In
this paper, we use q Lamb Mossbauer factor and anharmonic Lamb Mossbauer factor
to study this anharmoncity.Comment: Accpeted for publication in Physica
Near field and far field scattering of surface plasmon polaritons by one-dimensional surface defects
A rigorous formulation for the scattering of surface plasmon polaritons (SPP)
from a one-dimensional surface defect of any shape that yields the
electromagnetic field in the vacuum half-space above the vacuum-metal interface
is developed by the use of an impedance boundary condition. The electric and
magnetic near fields, the angular distribution of the far-field radiation into
vacuum due to SPP-photon coupling, and the SPP reflection and transmission
coefficients are calculated by numerically solving the k-space integral
equation upon which the formulation is based. In particular, we consider
Gaussian-shaped defects and study the dependence of the above mentioned
physical quantities on their 1/e half-width a and height h. SPP reflection is
significant for narrow defects; maximum reflection (plasmon mirrors) is
achieved for a~lambda/10. For increasing defect widths, protuberances and
indentations behave differently. The former give rise to a monotonic increase
of radiation at the expense of SPP transmission for increasing defect
half-width. Indentations exhibit a significant increase of radiation (decrease
of SPP transmission) for half-widths of the order of or smaller than the
wavelength, but tend to total SPP transmission in an oscillatory manner upon
further increasing the half-width. Light-emitters might thus be associated with
either wide indentations, or protuberances with widths that are of the order of
or smaller than the wavelength.Comment: REVTeX 3.1, 10 pages with 9 EPS figures (epsf macro
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
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