Soliton complexes in dissipative systems: vibrating, shaking and mixed soliton pairs

We show, numerically, that coupled soliton pairs in nonlinear dissipative systems modeled by the cubic-quintic complex Ginzburg-Landau equation can exist in various forms. They can be stationary, or they can pulsate periodically, quasiperiodically, or chaotically, as is the case for single solitons. In particular, we have found various types of vibrating and shaking soliton pairs. Each type is stable in the sense that a given bound state exists in the same form indefinitely. New solutions appear at special values of the equation parameters, thus bifurcating from stationary pairs. We also report the finding of mixed soliton pairs, formed by two different types of single solitons. We present regions of existence of the pair solutions and corresponding bifurcation diagrams

Non-SVEA models for supercontinuum generation

We know that the modified Korteweg-de Vries (mKdV), the sine-Gordon (sG), and the mKdV-sG models can describe few-cycle optical pulse propagation beyond the slowly-varying-envelope approximation in transparent media. We show numerically that these models are also able to describe the generation of supercontinua with spectral bandwidths of several octaves. Several mechanisms of spectral broadening are highlighted, involving self-phase modulation, parametric interactions of high harmonics, and few-cycle-soliton generation

Dynamics of the transition from polarization disorder to antiphase polarization domains in vector fiber lasers

We demonstrate that nonlinear polarization coupling in a fiber ring laser without polarization selective elements, subject to the effects of average anomalous dispersion, Kerr effect and nonlinear gain saturation, leads to the anti-synchronization of spatio-temporal chaos into ordered laminar states of orthogonal polarization temporal domains. Adjusting the polarization coupling may also lead to the generation of stable lattices of soliton trains with high duty cycle at repetition rates of hundreds of MHz, as well as trains of coupled dark and bright solitons

Baseband modulation instability as the origin of rogue waves

We study the existence and properties of rogue wave solutions in different nonlinear wave evolution models that are commonly used in optics and hydrodynamics. In particular, we consider Fokas-Lenells equation, the defocusing vector nolinear Schr\"odinger equation, and the long-wave-short-wave resonance equation. We show that rogue wave solutions in all of these models exist in the subset of parameters where modulation instability is present, if and only if the unstable sideband spectrum also contains cw or zero-frequency perturbations as a limiting case (baseband instability). We numerically confirm that rogue waves may only be excited from a weakly perturbed cw whenever the baseband instability is present. Conversely, modulation instability leads to nonlinear periodic oscillations

Phase-locked soliton pairs in a stretched-pulse fiber laser

We report the experimental observation of stable pulse pairs with a ±π/2 phase difference in a passively mode-locked stretched-pulse fiber ring laser. In our setup the stabilization of interacting subpicosecond pulses is obtained with a large range of pulse separations, namely, from 2.7 to 10 ps, without the need for external control. © 2002 Optical Society of AmericaPeer Reviewe

Polarization domain wall complexes in fiber lasers

International audienceWe present a simple theoretical model that explains polarization switching in fiber ring lasers operating with a normal path-averaged dispersion and a typical intermediate level of birefringence. Such polarization dynamics, based on a type of polarization-domain-wall (PDW) structures, agree qualitatively well with our experimental observations. We also stress the complex and chaotic nature of the observed polarization-switching states. This is corroborated by detailed numerical simulations that predict the buildup of consecutive and transient PDW structures at the subnanosecond scale, which are not fully resolved experimentally

Optical bullets and double bullet complexes in dissipative systems

We show that optical light bullets can coexist with double bullet complexes in nonlinear dissipative systems. Coexistence occurs for a relatively large range of the system parameters, and is associated with either marginal stability or bistable existence of the two dissipative soliton species. In the case of marginal stability, spontaneous transformations of single bullets into double bullet complexes are observed. Among the bistable cases, we show how both clockwise and anticlockwise rotating double bullet complexes can be formed out of the phase-controlled interaction of two single bullets. The internal dynamics of pulsating double bullet complexes, with oscillations in both the spatial separation between the two bullets and the bullet shape in time domain is also detailed