Parametric localized patterns and breathers in dispersive quadratic cavities

We study the formation of localized patterns arising in doubly resonant dispersive optical parametric oscillators. They form through the locking of fronts connecting a continuous-wave and a Turing pattern state. This type of localized pattern can be seen as a slug of the pattern embedded in a homogeneous surrounding. They are organized in terms of a homoclinic snaking bifurcation structure, which is preserved under the modification of the control parameter of the system. We show that, in the presence of phase mismatch, localized patterns can undergo oscillatory instabilities which make them breathe in a complex manner

Geometric parametric instability in periodically modulated graded-index multimode fibers

International audienceWe present a theoretical and numerical study of light propagation in graded-index (GRIN) mul-timode fibers where the core diameter has been periodically modulated along the propagation direction. The additional degree of freedom represented by the modulation permits to modify the intrinsic spatiotemporal dynamics which appears in multimode fibers. More precisely, we show that modulating the core diameter at a periodicity close to the self-imaging distance allows to induce a Moiré-like pattern, which modifies the geometric parametric instability gain observed in homogeneous GRIN fibers

Efficient modelling of nonlinear propagation in multimode graded-index fibers

International audienceWe develop an effective 1+1D model describing nonlinear propagation in multimode graded-index fibers. The model is able to quantitatively reproduce recently observed phenomena like geometric parametric instability and broadband dispersive wave emission

Modeling of quasi-phase-matched cavity enhanced second harmonic generation

We propose a mean-field model to describe second harmonic generation in a resonator made of a material with zincblende crystalline structure. The model is obtained through an averaging of the propagation equations and boundary conditions. It considers the phase-mismatched terms, which act as an effective Kerr effect. We analyze the impact of the different terms on the steady state solutions, highlighting the competition between nonlinearities

Localized structures formed through domain wall locking in cavity-enhanced second-harmonic generation

We analyze the formation of localized structures in cavity-enhanced second-harmonic generation. We focus on the phase-matched limit, and consider that fundamental and generated waves have opposite sign of group velocity dispersion. We show that these states form due to the locking of domain walls connecting two stable homogeneous states of the system, and undergo collapsed snaking. We study the impact of temporal walk-off on the stability and dynamics of these localized states.Comment: 4 pages, 5 figure

Grayness-dependent emission of dispersive waves from dark solitons in optical fibers

International audienceWe report the experimental observation of dispersive wave emission from gray solitons propagating in the normal dispersion region of an optical fiber. Besides observing for the first time the emission of a disper-sive wave from an isolated dark soliton, we show that the dispersive wave frequency and amplitude strongly depends on soliton grayness. This process can be explained by the higher-order dispersion contribution into the phase-matching condition and the grayness of the soliton. Numerical simulations and theoretical predictions are in good agreement with the experiments

Dissipative localized states and breathers in phase-mismatched singly resonant optical parametric oscillators: Bifurcation structure and stability

We study the emergence of dissipative localized states in phase mismatched singly resonant optical parametric oscillators. These states arise in two different bistable configurations due to the locking of front waves connecting the two coexisting states. In one of these configurations, the bistability is mediated by the coexistence of two uniform states. Here the localized states are organized in a collapsed snaking bifurcation structure. Moreover, these states undergo oscillatory instabilities which lead to a breathing behavior. When the bistability is related to the coexistence of a uniform state and a spatially periodic pattern, localized states are organized in a bifurcation structure similar to the standard homoclinic snaking. Performing an exhaustive bifurcation analysis, we characterize in detail the previous structures, their linear stability, and the modification of their dynamics as a function of the control parameters of the system.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Geometric parametric instability in periodically modulated graded-index multimode fibers

We present a theoretical and numerical study of light propagation in graded-index (GRIN) multimode fibers where the core diameter has been periodically modulated along the propagation direction. The additional degree of freedom represented by the modulation permits to modify the intrinsic spatiotemporal dynamics which appears in multimode fibers. More precisely, we show that modulating the core diameter at a periodicity close to the self-imaging distance allows to induce a Moir\'{e}-like pattern, which modifies the geometric parametric instability gain observed in homogeneous GRIN fibers

Dispersive wave emission from dark solitons and their collision in optical fibers

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Dispersive shock waves in optical fibers

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