0000000000146787
AUTHOR
Stefano Trillo
showing 22 related works from this author
Nonrecursive multiple shock formation via four-wave mixing: theory and experiment
2002
We show theoretically and experimentally that a beat signal propagating along a normally dispersive fiber can trigger the formation of multiple shocks. This phenomenon critically depends on the input frequency separation and power of the beat signal.
Bloch wave theory of modulational polarization instabilities in birefringent optical fibers
1997
The modulational instability gain spectra, of an arbitrarily polarized intense pump wave that experiences periodic nonlinear polarization rotation in a birefringent optical fiber, are derived by Floquet analysis. The predictions of the linearized analysis are confirmed by numerical simulations of the coupled nonlinear Schr\"odinger equations.
Even harmonic pulse train generation by cross-polarization-modulation seeded instability in optical fibers
2012
International audience; We show that, by properly adjusting the relative state of polarization of the pump and of a weak modulation, with a frequency such that at least one of its even harmonics falls within the band of modulation instability, one obtains a fully modulated wave at the second or higher even harmonic of the initial modulation. An application of this principle to the generation of a 80-GHz optical pulse train with high extinction ratio from a 40-GHz weakly modulated pump is experimentally demonstrated using a nonzero dispersion shifted fiber in the telecom C band.
Instabilities of four-wave mixing
2005
We predict that four-wave mixing driven by a dual frequency input undergoes different instability scenarios encompassing modulational instability or multiple shock formation in the anomalous and normal dispersion regime, respectively.
Cross-phase modulational instability induced by Raman scattering in highly birefringent fiber
2013
We report experimental and theoretical studies of Raman-induced cross-phase modulational instabilities (XPMI) in a high-birefringence, normally dispersive optical fiber. Experimental results reveal that the Raman-Stokes wave, generated by a quasi-CW pump beam, interacts with the latter to create a novel type of XPMI sidebands. These sidebands are characterized by a narrow gain bandwidth. The sideband frequencies are well reproduced by a linear stability analysis as well as by full numerical solutions of the coupled generalized nonlinear Schrödinger equations.
Four-wave mixing instabilities in telecom fibers
2012
Instabilities in fiber four-wave mixing are investigated, revealing the formation of colliding dispersive shock waves in the normal GVD regime and collective modulation instabilities in the anomalous GVD regime.
Nonlinear dynamics induced by optical shocks formation
2006
This paper reports on recent studies suggesting that optical shocks can rule the dynamics of cw (or quasi-cw) optical field propagating in glass when common phenomena such as four-wave mixing in fibers or catastrophic self-focusing in bulk are considered. The post-shock oscillations evolve into colliding dark solitons that determine the output pattern in a non-recurrent fashion. This scenario based on the defocusing nonlinear Schrodinger equation and its reduction to a hydrodynamical model is substantially confirmed by our experimental data consisting of recorded output spectra and temporal patterns retrieved from SHG-FROG traces. Numerical results also indicate that, during self-focusing, …
Large-signal enhanced frequency conversion in birefringent optical fibers: theory and experiments
1998
Strong frequency conversion among light waves propagating in a low-birefringence optical fiber in the normal-dispersion regime is experimentally investigated. Modulational gain spectra are obtained by injection of a signal orthogonally polarized with respect to a pump beam aligned with the slow fiber axis. Measurements reveal that, for signal power levels above a certain threshold value, peak conversion is obtained at pump signal frequency detunings far from the phase-matching condition. The large-signal three-wave mixing regime is well described by integrable nonlinear coupled-wave equations.
Generation of High-Repetition-Rate Dark Soliton Trains and Frequency Conversion in Optical Fibers
1998
Induced modurational polarization instability in birefringent fibers leads to trains of dark soliton-like pulses. Optimal large-signal cw and soliton frequency conversion is also analysed.
Giant collective incoherent shock waves in strongly nonlinear turbulent flows
2016
Contrary to conventional coherent shocks, we show theoretically and experimentally that nonlocal turbulent flows lead to the emergence of large-scale incoherent shock waves, which constitute a collective phenomenon of the incoherent field as a whole.
Vector Modulational Instabilities and Soliton Experiments
1999
In optical fibers, the interaction between nonlinear and dispersive effects leads to phenomena such as modulational instability (MI)[1, 2, 3, 4, 5, 6], in which a continuous or quasi-continuous wave undergoes a modulation of its amplitude or phase in the presence of noise or any other small perturbation. The perturbation can originate from quantum noise (spontaneous-MI) or from a frequency shifted signal wave (induced-MI). MI has been observed for the first time for a single pump wave propagating in a standard non birefringe.nt fiber (scalar MI)[7]. It has been shown that scalar MI only occurs when the group velocity dispersion (GVD) is negative (anomalous dispersion regime).
Impact of self-steepening on incoherent dispersive spectral shocks and collapse-like spectral singularities
2014
International audience; Incoherent dispersive shock waves and collapselike singularities have been recently predicted to occur in the spectral evolution of an incoherent optical wave that propagates in a noninstantaneous nonlinear medium. Here we extend this work by considering the generalized nonlinear Schrödinger equation. We show that self-steepening significantly affects these incoherent spectral singularities: (i) It leads to a delay in the development of incoherent dispersive shocks, and (ii) it arrests the incoherent collapse singularity. Furthermore, we show that the spectral collapselike behavior can be exploited to achieve a significant enhancement (by two orders of magnitudes) of…
Incoherent Dispersive Shocks and Spectral Collapse
2014
We predict the existence of incoherent dispersive shock waves and collapse-like singularities that occur in the spectral evolution of incoherent optical waves propagating in a noninstantaneous nonlinear medium.
Strong four-photon conversion regime of cross-phase-modulation-induced modulational instability
2000
We investigate theoretically and experimentally the strong conversion regime of parametric four-photon amplification or induced modulational instability in the normal dispersion regime of propagation in a highly birefringent fiber. Such optical mixing is observed by injecting a tunable linearly polarized (along the fast axis) anti-Stokes signal wave copropagating with a pump equisplitted between the fiber axes (i.e., linearly polarized at 45\ifmmode^\circ\else\textdegree\fi{}) which entail that the two pump modes experience cross-phase modulation. In agreement with a four-wave model developed to study the depleted regime of the mixing process, we observe that the strongest conversion occurs…
Temporal Dynamics of Incoherent Nonlinear Waves
2014
We review different formalisms describing incoherent waves: the wave turbulence kinetic equation, the Vlasov equation in analogy with Gravitation, the weak Langmuir turbulence equation describing spectral solitons and incoherent dispersive shocks.
Spectral dynamics of incoherent waves with a noninstantaneous nonlinear response
2013
We study the influence of a constant background noise on the dynamics of spectral incoherent solitons, which are incoherent structures sustained by a noninstantaneous (Raman-like) nonlinearity. As the level of the noise background increases, the incoherent wave enters a novel nonlinear regime characterized by oscillatory dynamics of the incoherent spectrum, which develop within a spectral cone during the propagation. In contrast to the conventional Raman-like spectral red shift, such incoherent spectral dynamics can be characterized by a significant spectral blue shift. On the basis of the kinetic wave theory, we derive explicit analytical expressions of these incoherent oscillatory spectra…
Observation of Optical Undular Bores in Multiple Four-Wave Mixing
2014
International audience; We demonstrate that wave-breaking dramatically affects the dynamics of nonlinear frequency conversion processes that operate in the regime of high efficiency (strong multiple four-wave mixing). In particular, by exploiting an all-optical-fiber platform, we show that input modulations propagating in standard telecom fibers in the regime of weak normal dispersion lead to the formation of undular bores (dispersive shock waves) that mimic the typical behavior of dispersive hydrodynamics exhibited, e.g., by gravity waves and tidal bores. Thanks to the nonpulsed nature of the beat signal employed in our experiment, we are able to clearly observe how the periodic nature of …
Shock-induced complex phase-space dynamics of strongly turbulent flows
2017
Shock waves have been thoroughly investigated during the last century in many different branches of physics. In conservative (Hamiltonian) systems the shock singularity is regularized by weak wave dispersion, thus leading to the formation of a rapidly and regular oscillating structure, usually termed in the literature dispersive shock wave (DSW), see e.g. [1]. Here, we show that this fundamental singular process of DSW formation can break down in a system of incoherent nonlinear waves. We consider the strong turbulent regime of a system of nonlocal nonlinear optical waves. We report theoretically and experimentally a characteristic transition: Strengthening the nonlocal character of the non…
Incoherent dispersive shocks in the spectral evolution of random waves
2013
We predict theoretically and numerically the existence of incoherent dispersive shock waves. They manifest themselves as an unstable singular behavior of the spectrum of incoherent waves that evolve in a noninstantaneous nonlinear environment. This phenomenon of "spectral wave breaking" develops in the weakly nonlinear regime of the random wave. We elaborate a general theoretical formulation of these incoherent objects on the basis of a weakly nonlinear statistical approach: a family of singular integro-differential kinetic equations is derived, which provides a detailed deterministic description of the incoherent dispersive shock wave phenomenon.
Giant collective incoherent shock waves in strong turbulence
2016
Contrary to conventional coherent shocks, we show theoretically and experimentally that nonlocal turbulent flows lead to the emergence of large-scale incoherent shock waves, which constitute a collective phenomenon of the incoherent field as a whole.
Emergence of long-range phase coherence in nonlocal nonlinear media
2017
The emergence of long range phase coherence among random nonlinear waves is a fascinating effect that characterizes many fundamental phenomena. For instance, the condensation of classical waves [1,2] is an important example of self-organization process that generates lot of interest as a classical analogue of quantum Bose-Einstein condensation. Wave condensation is known to be characterized by the emergence of long-range order and phase-coherence, in the sense that the correlation function of the wave amplitude does not decay at infinity. This property of long range phase coherence is fundamental, for instance for the manifestation of superfluid behaviors, or the generation of Bogoliubov so…
Collision de mascarets optiques dans les fibres optiques
2015
Une vidéo de la conférence est disponible à l'adresse suivante : https://youtu.be/c_R9D-VNMZo; National audience; Les instabilités optiques générées par mélange à quatre ondes sont étudiées expérimentalement dans les fibres optiques. En régime de dispersion normale, elles se traduisent par la génération d’ondes de choc et par des collisions successives de ces trains d’ondes.