1,095 research outputs found
Optical tsunamis: shoaling of shallow water rogue waves in nonlinear fibers with normal dispersion
In analogy with ocean waves running up towards the beach, shoaling of
prechirped optical pulses may occur in the normal group-velocity dispersion
regime of optical fibers. We present exact Riemann wave solutions of the
optical shallow water equations and show that they agree remarkably well with
the numerical solutions of the nonlinear Schr\"odinger equation, at least up to
the point where a vertical pulse front develops. We also reveal that extreme
wave events or optical tsunamis may be generated in dispersion tapered fibers
in the presence of higher-order dispersion
Spatiotemporal chaos and order in fiber lasers
We introduce a model that permits the unified description of the
emergence of different regimes of complex temporal structures in
noise-like or quasi-CW fiber lasers. The model is based on the
vector Ginzburg-Landau equation that also permits to reproduce
the experimentally observed polarization antiphase behavior and
the synchronization of spatiotemporal turbulence into polarizations
domain wall solitons
Instability and noise-induced thermalization of Fermi-Pasta-Ulam recurrence in the nonlinear Schr\"odinger equation
We investigate the spontaneous growth of noise that accompanies the nonlinear
evolution of seeded modulation instability into Fermi-Pasta-Ulam recurrence.
Results from the Floquet linear stability analysis of periodic solutions of the
three-wave truncation are compared with full numerical solutions of the
nonlinear Schr\"odinger equation. The predicted initial stage of noise growth
is in good agreement with simulations, and is expected to provide further
insight in the subsequent dynamics of the field evolution after recurrence
breakup
Temporal cavity soliton formation in an anomalous dispersion cavity fiber laser: Comment
A recent paper [J. Opt. Soc. Am. B 31, 3050 (2014) [CrossRef] ] reports the experimental observation of the generation of stable pulse trains in a ring fiber laser. Contrary to what is stated, the theory published in that paper does not support the claim that the generation mechanism of the pulse train is the cavity-induced modulation instability effect
Comment on GHz pulse train generation in fiber lasers by cavity induced modulation instability
A recent invited paper (Tang et al., 2014) reports the experimental observation of the generation of stable
pulse trains in a ring fiber laser with repetition rates varying in the range between 3 GHz and 285 GHz.
Contrary to what is stated, the theory published in that invited paper does not support the claim that the
generation mechanism of the pulse train is the cavity induced modulation instability effect
Mid-Infrared Soliton and Raman Frequency Comb Generation in Silicon Microrings
We numerically study the mechanisms of frequency comb generation in the
mid-infrared spectral region from cw pumped silicon microring resonators.
Coherent soliton comb generation may be obtained even for a pump with zero
linear cavity detuning, through suitable control of the effective lifetime of
free-carriers from multiphoton absorption, which introduces a nonlinear cavity
detuning via free-carrier dispersion. Conditions for optimal octave spanning
Raman comb generation are also described
Bragg grating rogue wave
We derive the rogue wave solution of the classical massive Thirring model,
that describes nonlinear optical pulse propagation in Bragg gratings. Combining
electromagnetically induced transparency with Bragg scattering four-wave
mixing, may lead to extreme waves at extremely low powers
Parametric Frequency Conversion of Short Optical Pulses Controlled by a CW Background
We predict that parametric sum-frequency generation of an ultra-short pulse
may result from the mixing of an ultra-short optical pulse with a
quasi-continuous wave control. We analytically show that the intensity, time
duration and group velocity of the generated idler pulse may be controlled in a
stable manner by adjusting the intensity level of the background pump
Dynamics of microresonator frequency comb generation: models and stability
Microresonator frequency combs hold promise
for enabling a new class of light sources that are simultaneously
both broadband and coherent, and that could
allow for a profusion of potential applications. In this article,
we review various theoretical models for describing
the temporal dynamics and formation of optical frequency
combs. These models form the basis for performing numerical
simulations that can be used in order to better understand
the comb generation process, for example helping to
identify the universal combcharacteristics and their different
associated physical phenomena. Moreover, models allow
for the study, design and optimization of comb properties
prior to the fabrication of actual devices. We consider
and derive theoretical formalisms based on the Ikeda map,
the modal expansion approach, and the Lugiato-Lefever
equation. We further discuss the generation of frequency
combs in silicon resonators featuring multiphoton absorption
and free-carrier effects. Additionally, we review comb
stability properties and consider the role of modulational
instability as well as of parametric instabilities due to the
boundary conditions of the cavity. These instability mechanisms
are the basis for comprehending the process of frequency
comb formation, for identifying the different dynamical
regimes and the associated dependence on the
comb parameters. Finally, we also discuss the phenomena
of continuous wave bi- and multistability and its relation
to the observation of mode-locked cavity solitons
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