百瓦级飞秒棒状光子晶体光纤激光器OA

[Background]High-power femtosecond fiber lasers are essential tools for advanced applications in ultrafast science,precision manufacturing,and nonlinear optics.However,achieving hundred-watt-level output while maintaining high beam quality and short pulse duration remains challenging due to nonlinear effects and transverse mode instabilities.[Purpose]This work aims to develop a high-power femtosecond fiber laser system based on chirped-pulse amplification(CPA),using rod-type photonic crystal fiber as the gain medium,to achieve hundred-watt-level output with high efficiency and stable beam quality.[Methods]The system adopts a rod-type photonic crystal fiber as the main amplifier.Backward pumping combined with double-pass amplification in a single rod fiber is implemented to enhance pump-to-signal conversion efficiency.Nonlinear effects are mitigated by employing a large mode area fiber,short gain length,and proper chirped-pulse management.A double-grating compressor is used for final pulse compression.[Results]The amplifier achieves a pump-to-signal conversion efficiency exceeding 60%.The system delivers pulses with a central wavelength of 1 033 nm,a repetition rate of 1 MHz,a single-pulse energy of 162 μJ,and a pulse duration of 233 fs.The output beam ellipticity is better than 95%.The overall pump-to-compressed-signal efficiency reaches 54%.[Conclusions]The demonstrated system achieves high repetition rate,high average power,and ultrashort pulse duration simultaneously,providing a novel and practical scheme for hundred-watt-level femtosecond fiber lasers.This approach offers new opportunities for applications requiring stable,high-brightness ultrafast sources.