742 research outputs found
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
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
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
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
The Design of Random Surfaces with Specified Scattering Properties: Surfaces that Suppress Leakage
We present a method for generating a one-dimensional random metal surface of
finite length L that suppresses leakage, i.e. the roughness-induced conversion
of a surface plasmon polariton propagating on it into volume electromagnetic
waves in the vacuum above the surface. Perturbative and numerical simulation
calculations carried out for surfaces generated in this way show that they
indeed suppress leakage.Comment: Revtex 6 pages (including 4 figures
Nanogroove array on thin metallic film as planar lens with tunable focusing
Numerical results for the distributions of light transmitted through metallic
planar lenses composed of symmetric nanogroove arrays on the surfaces of a gold
film are presented and explained. Both the near- and far-field distributions of
the intensity of light transmitted are calculated by using a Green's function
formalism. Results for an optimal transverse focus based on a quadratic
variation of groove width are obtained. Meanwhile, a significant dependence of
the focal length on the wavelength of light incident from the air side through
the gold film into a dielectric substrate is found for this detector
configuration.Comment: 14 pages, 6 figure
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