Ultrahigh repetition frequency femtosecond fiber laser system applied to material micromachining

Abstract

The invention discloses an ultrahigh repetition frequency femtosecond fiber laser system applied to material micromachining. The ultrahigh repetition frequency femtosecond fiber laser system comprises a gain switch semiconductor seed source which is used for generating a GHz repetition frequency picosecond-order seed pulse, a signal light regeneration system used for generating seed pulses with high coherence degree and near conversion limit, an optical fiber pre-amplifier used for performing power pre-amplification and spectrum broadening on the picosecond seeds, a pulse selector used for generating a burst pulse string, a pulse pre-chirp device used for optimizing the amplification quality in the amplification process of the seed pulse, an optical fiber power amplifier used for improving the average power and pulse energy of the pulse, and a pulse compressor used for compensating chirp of the amplified pulse to obtain ultrashort pulse output close to the conversion limit. By the adoption of the ultrahigh repetition frequency femtosecond fiber laser system, high-power, high-beam-quality and high-stability linear polarization femtosecond pulse laser output can be achieved, the gain modulation semiconductor laser which is mature, stable, free of a saturable absorber loss device and high in reliability is adopted to replace a traditional mode-locked oscillator and a frequency superposition module, and the ultrahigh repetition frequency femtosecond fiber laser system is more suitable for being applied to the field of industrial production.

Description

technical field [0001] The invention belongs to the field of laser technology and nonlinear optics, in particular to an ultra-high repetition frequency femtosecond fiber laser system applied to material microprocessing. Background technique [0002] Femtosecond pulses have important application values ​​in precision frequency measurement, material microprocessing, laser surgery, multiphoton biomedical imaging, and scientific research due to their ultrafast time-domain characteristics and high peak power. Among them, with the rapid development of the consumer electronics industry, the advantages of femtosecond lasers in the field of precision material processing have become increasingly prominent. When femtosecond pulses are used for material processing, the interaction between the laser and the material is "frozen" in the process of electrons being stimulated to absorb and store energy. The ultrashort pulse uses laser photons to directly destroy the bonding bonds of the targ...

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Problems solved by technology

However, this type of laser also has inherent shortcomings, including poor pulse coherence and temporal stability, wide output pulse width, large pulse amplitude and phase noise, and low pulse spectral side-mode suppression ratio, etc.

Therefore, such lasers cannot compare with traditional mode-locked lasers in terms of output pulse width, pulse coherence, and pulse signal-to-noise ratio.

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