Bidirectional ultrafast fiber lasers present an attractive solution,enabling the generation of two mutually coherent ultrashort pulse trains in a simple and turnkey system.Still,the lack of a comprehensive numerical m...Bidirectional ultrafast fiber lasers present an attractive solution,enabling the generation of two mutually coherent ultrashort pulse trains in a simple and turnkey system.Still,the lack of a comprehensive numerical model describing steady-state bidirectional generation,and even less ultrafast soliton breakdowns and collisions,is obstructing the achievement of the performance compared with unidirectional lasers.In this paper,we have experimentally investigated real-time build-up dynamics of counter-propagating solitons in an ultrafast ring Er-doped fiber laser via the dispersive Fourier transform methodology.We parade that counter-propagating pulses experience independent build-up dynamics from modulation instability,undergoing breathing dynamics and diverging subordinate pulse structure formation and annihilation to a stable bidirectional pulse train.Yet,the interaction of pulses in the cavity presents the key underlying phenomenon driving formation evolution distinct from unidirectional pulse build-up.Our findings will provide physical foundations for bidirectional ultrafast fiber laser design to carry forward their application.展开更多
Side-pumping fibre combiners offer several advantages in fibre laser design,including distributed pump absorption,reduced heat load,and improved flexibility and reliability.These benefits are particularly important fo...Side-pumping fibre combiners offer several advantages in fibre laser design,including distributed pump absorption,reduced heat load,and improved flexibility and reliability.These benefits are particularly important for all-fibre lasers and amplifiers operating in the mid-IR wavelength range and based on soft-glass optical fibres.However,conventional fabrication methods face limitations due to significant differences in the thermal properties of pump-delivering silica fibres and signal-guiding fluoride-based fibres.To address these challenges,this work introduces a design for a fuse-less side-polished(D-shaped)fibre-based pump combiner comprising multimode silica and double-clad fluoride-based fibres.The results demonstrate stable coupling efficiency exceeding 80%at a 980-nm wavelength over 8 hours of continuous operation under active thermal control.The developed pump combiner has also been successfully integrated into a linear Er-doped fibre laser cavity,showing continuous-wave generation at 2731 or 2781-nm central wavelength with an output power of 0.87 W.Overall,this innovative approach presents a simple,repeatable,and reproducible pump combiner design that opens up new possibilities for leveraging fibre-based component technology in soft glass matrices and other emerging fibres with unique compositions.展开更多
基金Royal Academy of Engineering and Global Challenges Research FundH2020 Marie Sklodowska-Curie Actions(COFUND-MULTIPLY).
文摘Bidirectional ultrafast fiber lasers present an attractive solution,enabling the generation of two mutually coherent ultrashort pulse trains in a simple and turnkey system.Still,the lack of a comprehensive numerical model describing steady-state bidirectional generation,and even less ultrafast soliton breakdowns and collisions,is obstructing the achievement of the performance compared with unidirectional lasers.In this paper,we have experimentally investigated real-time build-up dynamics of counter-propagating solitons in an ultrafast ring Er-doped fiber laser via the dispersive Fourier transform methodology.We parade that counter-propagating pulses experience independent build-up dynamics from modulation instability,undergoing breathing dynamics and diverging subordinate pulse structure formation and annihilation to a stable bidirectional pulse train.Yet,the interaction of pulses in the cavity presents the key underlying phenomenon driving formation evolution distinct from unidirectional pulse build-up.Our findings will provide physical foundations for bidirectional ultrafast fiber laser design to carry forward their application.
基金funded by the German Federal Ministry of Education and Research(BMBF)and supervised by the VDI Technology Center under number 13N15464"Leibniz Center for Photonics in Infection Research(LPI):Multidimensional,multimodal,intelligent imaging platforms"The authors also acknowledge the support from the European Regional Development Fund.
文摘Side-pumping fibre combiners offer several advantages in fibre laser design,including distributed pump absorption,reduced heat load,and improved flexibility and reliability.These benefits are particularly important for all-fibre lasers and amplifiers operating in the mid-IR wavelength range and based on soft-glass optical fibres.However,conventional fabrication methods face limitations due to significant differences in the thermal properties of pump-delivering silica fibres and signal-guiding fluoride-based fibres.To address these challenges,this work introduces a design for a fuse-less side-polished(D-shaped)fibre-based pump combiner comprising multimode silica and double-clad fluoride-based fibres.The results demonstrate stable coupling efficiency exceeding 80%at a 980-nm wavelength over 8 hours of continuous operation under active thermal control.The developed pump combiner has also been successfully integrated into a linear Er-doped fibre laser cavity,showing continuous-wave generation at 2731 or 2781-nm central wavelength with an output power of 0.87 W.Overall,this innovative approach presents a simple,repeatable,and reproducible pump combiner design that opens up new possibilities for leveraging fibre-based component technology in soft glass matrices and other emerging fibres with unique compositions.
