625 research outputs found
Cavity Soliton Laser based on mutually coupled semiconductor microresonators
We report on experimental observation of localized structures in two mutually
coupled broad-areahttp://hal.archives-ouvertes.fr/images/calendar.gif
semiconductor resonators. These structures coexist with a dark homogeneous
background and they have the same properties as cavity solitons without
requiring the presence of a driving beam into the system. They can be switched
individually on and off by means of a local addressing beam
Cavity Light Bullets: 3D Localized Structures in a Nonlinear Optical Resonator
We consider the paraxial model for a nonlinear resonator with a saturable
absorber beyond the mean-field limit and develop a method to study the
modulational instabilities leading to pattern formation in all three spatial
dimensions. For achievable parametric domains we observe total radiation
confinement and the formation of 3D localised bright structures. At difference
from freely propagating light bullets, here the self-organization proceeds from
the resonator feedback, combined with diffraction and nonlinearity. Such
"cavity" light bullets can be independently excited and erased by appropriate
pulses, and once created, they endlessly travel the cavity roundtrip. Also, the
pulses can shift in the transverse direction, following external field
gradients.Comment: 4 pages, 3 figures, simulations files available at
http://www.ba.infn.it/~maggipin/PRLmovies.htm, submitted to Physical Review
Letters on 24 March 200
Stable autosolitons in dispersive media with saturable gain and absorption
We introduce the simplest one-dimensional model of a dispersive optical
medium with saturable dissipative nonlinearity and filtering (dispersive loss)
which gives rise to stable solitary pulses (autosolitons). In the particular
case when the dispersive loss is absent, the same model may also be interpreted
as describing a stationary field in a planar optical waveguide with uniformly
distributed saturable gain and absorption. In a certain region of the model's
parameter space, two coexisting solitary-pulse solutions are found numerically,
one of which may be stable. Solving the corresponding linearized eigenvalue
problem, we identify stability borders for the solitary pulses in their
parametric plane. Beyond one of the borders, the symmetric pulse is destroyed
by asymmetric perturbations, and at the other border it undergoes a Hopf
bifurcation, which may turn it into a breather.Comment: A latex text file and four ps files with figures. Physics Letters A,
in pres
Mid-Band Dissipative Spatial Solitons
We show dissipative spatial solitons in nonlinear optical micro-resonators in
which the refractive index is laterally modulated. In addition to "normal" and
"staggered" dissipative solitons, similar to those in spatially modulated
conservative systems, a narrow "mid-band" soliton is shown, having no
counterparts in conservative systems
Interaction of cavity solitons in degenerate optical parametric oscillators
Numerical studies together with asymptotic and spectral analysis establish
regimes where soliton pairs in degenerate optical parametric oscillators fuse,
repel, or form bound states. A novel bound state stabilized by coupled internal
oscillations is predicted.Comment: 3 page
Obtaining single-cycle pulses from a mode-locked laser
In all existing mode-locked lasers, the ultimate limit on the output pulse duration is set by the bandwidth of the gain medium. Yet the technique of coherent mode locking allows one to generate broadband pulses from a laser with a linearly narrowband active medium by exploiting the coherent properties of the amplifier. In this work we numerically demonstrate how to use this technique for the generation of single-cycle pulses directly from a mode-locked oscillator
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