Harnessing pulse generation from an ultrafast laser is a challenging task as reaching a specific mode-locked regime generally involves adjusting multiple control parameters, in connection with a wide range of accessible pulse dynamics. Machine-learning tools have recently shown promising for the design of smart lasers that can tune themselves to desired operating states. Yet, machine-learning algorithms are mainly designed to target regimes of parameter-invariant, stationary pulse generation, while the intelligent excitation of evolving pulse patterns in a laser remains largely unexplored. Breathing solitons exhibiting periodic oscillatory behavior, emerging as ubiquitous mode-locked regime of ultrafast fibre lasers, are attracting considerable interest by virtue of their connection with a range of important nonlinear dynamics, such as exceptional points, and the Fermi-Pasta-Ulam paradox. Here, we implement an evolutionary algorithm for the self-optimisation of the breather regime in a fibre laser mode-locked through a four-parameter nonlinear polarisation evolution. Depending on the specifications of the merit function used for the optimisation procedure, various breathing-soliton states are obtained, including single breathers with controllable oscillation period and breathing ratio, and breather molecular complexes with a controllable number of elementary constituents. Our work opens up a novel avenue for exploration and optimisation of complex dynamics in nonlinear systems.
Unified model for breathing solitons in fibre lasers: Mechanisms across below- and above-threshold regimes
State Key Laboratory of Precision Spectroscopy, and Hainan Institute, East China Normal University（精密光谱科学与技术国家重点实验室、海南研究院，华东师范大学）；Collaborative Innovation Center of Extreme Optics, Shanxi University（极端光学协同创新中心，山西大学）；Chongqing Key Laboratory of Precision Optics, Chongqing Institute of East China Normal University（精密光学重庆市重点实验室，华东理工大学重庆研究院）；Université Bourgogne Europe, CNRS, Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB)（勃艮第欧洲大学，法国国家科学研究中心，勃艮第卡诺跨学科实验室）；VPIphotonics GmbH（VPI光子学有限公司）；Aston Institute of Photonic Technologies, Aston University（阿斯顿光子技术研究所，阿斯顿大学）；Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud (INFN-LNS)（意大利国家核物理研究所，南实验室）
Pulse-by-pulse programmable synthesis of ultrafast optical waveforms
East China Normal University（华东师范大学）；Chongqing Institute of East China Normal University（华东师范大学重庆研究院）；Polytechnique Montréal（蒙特利尔高等理工学院）；University of New Mexico（新墨西哥大学）
Self-starting Dynamics in All-fibre All-Normal-Dispersion Thulium Mamyshev oscillator
Leibniz Institute of Photonics Technology（莱布尼茨光子技术研究所）；Aston Institute of Photonics Technologies, Aston University（阿斯顿大学阿斯顿光子技术研究所）；Prokhorov General Physics Institute of the Russian Academy of Sciences, Dianov Fiber Optics Research Center（俄罗斯科学院普洛霍罗夫普通物理研究所季亚诺夫光纤研究中心）；Institute of Chemistry of High Purity Substances of the Russian Academy of Sciences（俄罗斯科学院高纯物质化学研究所）
