779 research outputs found
Coherent switching of semiconductor resonator solitons
We demonstrate switching on and off of spatial solitons in a semiconductor
microresonator by injection of light coherent with the background illumination.
Evidence results that the formation of the solitons and their switching does
not involve thermal processes.Comment: 3 pages, 5 figure
Spatial Resonator Solitons
Spatial solitons can exist in various kinds of nonlinear optical resonators
with and without amplification. In the past years different types of these
localized structures such as vortices, bright, dark solitons and phase solitons
have been experimentally shown to exist. Many links appear to exist to fields
different from optics, such as fluids, phase transitions or particle physics.
These spatial resonator solitons are bistable and due to their mobility suggest
schemes of information processing not possible with the fixed bistable elements
forming the basic ingredient of traditional electronic processing. The recent
demonstration of existence and manipulation of spatial solitons in emiconductor
microresonators represents a step in the direction of such optical parallel
processing applications. We review pattern formation and solitons in a general
context, show some proof of principle soliton experiments on slow systems, and
describe in more detail the experiments on semiconductor resonator solitons
which are aimed at applications.Comment: 15 pages, 32 figure
Dark polariton-solitons in semiconductor microcavities
We report the existence, symmetry breaking and other instabilities of dark
polariton-solitons in semiconductor microcavities operating in the strong
coupling regime. These half-light half-matter solitons are potential candidates
for applications in all-optical signal processing. Their excitation time and
required pump powers are a few orders of magnitude less than those of their
weakly coupled light-only counterparts.Comment: submitted to PR
Realization of a semiconductor-based cavity soliton laser
The realization of a cavity soliton laser using a vertical-cavity
surface-emitting semiconductor gain structure coupled to an external cavity
with a frequency-selective element is reported. All-optical control of bistable
solitonic emission states representing small microlasers is demonstrated by
injection of an external beam. The control scheme is phase-insensitive and
hence expected to be robust for all-optical processing applications. The
motility of these structures is also demonstrated
Hadron Resonance Gas Model with Induced Surface Tension
Here we present a physically transparent generalization of the multicomponent
Van der Waals equation of state in the grand canonical ensemble. For the
one-component case the third and fourth virial coefficients are calculated
analytically. It is shown that an adjustment of a single model parameter allows
us to reproduce the third and fourth virial coefficients of the gas of hard
spheres with small deviations from their exact values. A thorough comparison of
the compressibility factor and speed of sound of the developed model with the
one and two component Carnahan-Starling equation of state is made. It is shown
that the model with the induced surface tension is able to reproduce the
results of the Carnahan-Starling equation of state up to the packing fractions
0.2-0.22 at which the usual Van der Waals equation of state is inapplicable. At
higher packing fractions the developed equation of state is softer than the gas
of hard spheres and, hence, it breaks causality in the domain where the
hadronic description is expected to be inapplicable. Using this equation of
state we develop an entirely new hadron resonance gas model and apply it to a
description of the hadron yield ratios measured at AGS, SPS, RHIC and ALICE
energies of nuclear collisions. The achieved quality of the fit per degree of
freedom is about 1.08. We confirm that the strangeness enhancement factor has a
peak at low AGS energies, while at and above the highest SPS energy of
collisions the chemical equilibrium of strangeness is observed. We argue that
the chemical equilibrium of strangeness, i.e. , observed
above the center of mass collision energy 4.3 GeV may be related to the
hadronization of quark gluon bags which have the Hagedorn mass spectrum, and,
hence, it may be a new signal for the onset of deconfinement
Hard-core Radius of Nucleons within the Induced Surface Tension Approach
In this work we discuss a novel approach to model the hadronic and nuclear
matter equations of state using the induced surface tension concept. Since the
obtained equations of state, classical and quantum, are among the most
successful ones in describing the properties of low density phases of strongly
interacting matter, they set strong restrictions on the possible value of the
hard-core radius of nucleons. Therefore, we perform a detailed analysis of its
value which follows from hadronic and nuclear matter properties and find the
most trustworthy range of its values: the hard-core radius of nucleons is
0.30--0.36 fm. A comparison with the phenomenology of neutron stars implies
that the hard-core radius of nucleons has to be temperature and density
dependent.Comment: 12 pages, 4 figures, references added, typos correcte
Patterns and localized structures in bistable semiconductor resonators
We report experiments on spatial switching dynamics and steady state
structures of passive nonlinear semiconductor resonators of large Fresnel
number. Extended patterns and switching front dynamics are observed and
investigated. Evidence of localization of structures is given.Comment: 5 pages with 9 figure
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