Recent machine-learning applications in ultrafast nonlinear fibre photonics

Dissipative Optical Breather Molecular Complexes

We demonstrate different types of breathing soliton complexes in a mode-locked fibre laser: multi-breather molecules, and molecular complexes arising from the binding of two breather-pair molecules or a breather-pair molecule and a single breather.

Frequency locking of a breather fibre laser, fairy tree and devil's staircase

Breathing solitons exhibiting periodic oscillatory behaviour form an important part of many different classes of nonlinear wave systems. Recently, thanks to the development of real-time detection techniques, they have also emerged as a ubiquitous mode-locked regime of ultrafast fibre lasers [1,2]. The excitation of breather oscillations in a laser naturally triggers a second characteristic frequency in the system, which therefore shows competition between the cavity repetition frequency and the breathing frequency. The theoretical model describing nonlinear systems with two competing frequencies predicts frequency locking, in which the system locks into a resonant periodic response featurin…

Pulsating Solitons in Mode-Locked Fibre Lasers

International audience; We report on our direct experimental observation of a new regime of operation of passively mode-locked fibre lasers where the laser oscillator generates pulsating solitons with extreme ratios of maximal to minimal intensities in each period of pulsations. The soliton spectra also experience large periodic broadening and compression. Spatio-temporal intensity and dispersive Fourier-transformation measurements enable us to capture such transient dynamics in real time.

Self-Optimising Breather Ultrafast Fibre Laser

We demonstrate the self-optimisation of the breather regime in an ultrafast fibre laser through an evolutionary algorithm. Depending on the specified merit function, single breathers with controllable breathing ratio and period, and breather molecular complexes with a controllable number of constituents can be obtained.

Control of complex nonlinear wave dynamics in dissipative systems by machine learning

Ultrafast mode-locked fibre lasers exploiting nonlinearity in the pulse formation process are well-known to display a rich landscape of "dissipative soliton'' dynamics, which results from the interplay of the nonlinearity with dispersion and dissipation. Reaching a desired operating regime in a fibre laser generally depends on precisely adjusting multiple parameters in a high-dimensional space, in connection with the wide range of accessible pulse dynamics, which is usually performed through a trial-and-error experimental procedure, due to the lack of analytic relationship between the cavity parameters and the pulse features. The practical difficulties associated with such a procedure can b…

Breather Molecular Complexes in a Passively Mode‐Locked Fiber Laser

International audience; Breathing solitons are nonlinear waves in which the energy concentrates in a localized and oscillatory fashion. Similarly to stationary solitons, breathers in dissipative systems can form stable bound states displaying molecule-like dynamics, which are frequently called breather molecules. So far, the experimental observation of optical breather molecules and the real-time detection of their dynamics are limited to diatomic molecules, that is, bound states of only two breathers. In this work, the observation of different types of breather complexes in a mode-locked fiber laser: multibreather molecules, and molecular complexes originating from the binding of two breat…

Auto-setting breather mode-locked fibre laser

International audience

Breather Dynamics in Ultrafast Fibre Lasers and Their Intelligent Control

We review our recent work on the dynamics of breathing solitons in fibre lasers, including single breathers, breather molecular complexes, breather explosions and breather frequency locking at Farey fractions, and their control by genetic algorithms.

Breather laser dynamics and their intelligent control

Breathers are localized structures showing periodic variations in parameters. They are found in various fields of science, and are currently attracting significant research interest in virtue of their relationship with a rich set of important nonlinear phenomena. They have recently emerged as a universal ultrashort pulse regime in passively mode-locked fibre lasers. Here, we reviewed our recent works in this fast-growing field, including the first observation of breathing dissipative solitons and their complexes in mode-locked fibre lasers[1-3], breather explosions[4], and intelligent control of breathers over breathing periods, breathing ratios, and the number of breathers[5]. Finally, fra…

Machine learning for ultrafast nonlinear photonics

Accrochage de fréquence dans un laser à fibre à respiration : observation de l’arbre de Farey et de l’escalier du diable

Contrairement au soliton brillant, les solitons à respiration présentent un comportement oscillatoire périodique. L’utilisation des fibres optiques a grandement facilité leur observation: l’interaction sur une grande distance entre la non-linéarité Kerr et la dispersion, en la quasi-absence de dissipation a ainsi permis la caractérisation fine des solitons à respiration d’Akhmediev, de Ma ou bien encore de leur cas limite, le soliton de Peregrine.Grâce au développement des techniques de détection en temps réel, les cavités laser à fibre offrent une autre plateforme extrêmement intéressante. Dans le contexte des lasers ultrarapides à modes bloqués, la génération d’impulsions à respiration co…

Façonnage optique intra-cavité dans un laser impulsionnel à fibre

National audience