Parametric self-trapping in the presence of randomized quasi phase matching
We report on experimental evidence of parametric spatial solitons in a quadratic crystal with randomized periodic ferroelectric poling. Two-color self-focusing via quadratic cascading overcomes the diffractive nature of both fundamental and frequency-doubled beams.
Nonlinear dynamics induced by optical shocks formation
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, …
Dissipative shock waves in all-normal-dispersion mode-locked fiber lasers
4 pags.; 4 figs.; OCIS codes: (140.4050) Mode-locked lasers; (140.3510) Lasers, fiber.
Emergence of long-range phase coherence in nonlocal nonlinear media
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…