282 research outputs found
Stokes parameters for light scattering from a Faraday-active sphere
We present an exact calculation for the scattering of light from a single
sphere made of Faraday-active material, to first order in the external magnetic
field. We use a recent expression for the T-matrix of a Mie scatterer in a
magnetic field to compute the Stokes parameters in single scattering that
describe completely flux and polarization of the scattered light.Comment: 17 pages, 5 figures, Latex, accepted for publication in JQSR
Transverse confinement of waves in 3D random media
We study the transmission of a tightly focused beam through a thick slab of
3D disordered medium in the Anderson localized regime. We show that the
transverse profile of the transmitted beam exhibits clear signatures of
Anderson localization and that its mean square width provides a direct measure
of the localization length. For a short incident pulse, the width is
independent of absorption.Comment: 4 pages, 3 figure
Weak localization of short pulses in disordered waveguides
We consider the phenomenon of weak localization of a short wave pulse in a
quasi-1D disordered waveguide. We show that the long-time decay of the average
transmission coefficient is not purely exponential, in contradiction with
predictions of the diffusion theory. The diffusion theory breaks down
completely for times exceeding the Heisenberg time. We also study the survival
probability of a quantum particle in a disordered waveguide and compare our
results with previous calculations using the super-symmetric nonlinear sigma
model.Comment: 4 pages, to appear in Acta Phys. Pol. A (Proceedings of the 2nd
Workshop on Quantum Chaos and Localization Phenomena, May 19-22, 2005,
Warsaw
Magneto-chiral scattering of light: a new optical manifestation of chirality
We have investigated multiple scattering of light in systems subject to
magneto-chiral (MC) effects. Our medium consists of magneto-optically active
dipoles placed in a chiral geometry under the influence of an external magnetic
field. We have calculated, for the first time, the total and the differential
scattering MC cross sections of this system, explicitely showing that they are
proportional to pseudoscalar quantities. This provides a new optical measure
for the degree of chirality, a pseudoscalar g, of an arbitrary geometrical
configuration of scatterers based on its scattering properties. We have
calculated g for some simple chiral systems and we have even used it to probe
the degree of optical chirality of random systems. Finally, we have compared
with other recently defined chiral measures in literature.Comment: 18 pages, 6 figures, RevTeX. Submitted to PR
Dynamics of weakly localized waves
We develop a transport theory to describe the dynamics of (weakly) localized
waves in a quasi-1D tube geometry both in reflection and in transmission. We
compare our results to recent experiments with microwaves, and to other
theories such as random matrix theory and supersymmetric theory.Comment: RevTeX, 4 pages, 2 figure
Role of mean free path in spatial phase correlation and nodal screening
We study the spatial correlation function of the phase and its derivative,
and related, fluctuations of topological charge, in two and three dimensional
random media described by Gaussian statistics. We investigate their dependence
on the scattering mean free path.Comment: 7 pages, 6 figures. submitted to Europhys. Let
Dynamics of Anderson localization in open 3D media
We develop a self-consistent theoretical approach to the dynamics of Anderson
localization in open three-dimensional (3D) disordered media. The approach
allows us to study time-dependent transmission and reflection, and the
distribution of decay rates of quasi-modes of 3D disordered slabs near the
Anderson mobility edge.Comment: 4 pages, 4 figure
Radiation of Optical Angular Momentum by a Dipole Source inside a Magneto-optical Environment
Radiation of electromagnetic energy by electric or magnetic multipole sources
can be modified by their local environment. In this work we demonstrate that a
magneto-optical environment of an unpolarized dipole source induces the
radiation of angular momentum into space. This radiation benefits from
Purcell-enhancement.Comment: 4 figures, 1 Table, submitte
Controlled manipulation of light by cooperative response of atoms in an optical lattice
We show that a cooperative atom response in an optical lattice to resonant
incident light can be employed for precise control and manipulation of light on
a subwavelength scale. Specific collective excitation modes of the system that
result from strong light-mediated dipole-dipole interactions can be addressed
by tailoring the spatial phase-profile of the incident light. We demonstrate
how the collective response can be used to produce optical excitations at
well-isolated sites on the lattice.Comment: 8 pages, 1 figur
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