Research On Fabrication Technology Of High-Power Pulse Laser And Fiber Optic Device

Q-switched pulsed fiber lasers have the advantages of good beam quality,high electro-optical conversion efficiency,high single pulse energy,and adjustable pulse repetition frequency.They are widely used in industrial,aerospace,biomedical,and sensor fields.The research on the fabrication technology of laser and its key optical fiber devices is of great significance.In this paper,the research on the fabrication technology of optic al fiber devices such as fiber combiner,mode field adapter,cladding optical stripper is carried out.Based on the above devices,pulsed fiber lasers based on acousto-optic Q-switched technology are developed,and Q-switched pulsed fiber lasers are analyzed.Output spectral characteristics and pulse output characteristics are also measured.The specific research contents of this thesis are as follows:1.The operation theory of pulsed fiber laser based on acousto-optic Qswitching technology is described.The cladding pump coupling theory and MOPA amplification principle are explained and the operation process of pulsed laser is analyzed based on the laser rate equation.2.The working principle of key optical fiber devices is introduced,the key preparation technology of optical fiber devices is studied.(2+1)×1 fiber combiner,(6+1)×1 fiber combiner,fiber mode field adapter,20/400 cladding optical stripper and 80/400 cladding optical stripper were prepared.The preparation steps of optical fiber devices were described in detail.3.Based on the reverse pumping scheme,a pulsed fiber laser seed source was constructed,and the pulse repetition frequency,pulse width,pulse wave and other output characteristics and spectral data of the 50 k Hz,100 k Hz,and 200 k Hz with different pulse repetition frequencies were studied.4.Based on the MOPA amplification structure,a laser amplification stage was built,and three sets of laser seed sources with pulse repetition frequencies of 50 k Hz,100 k Hz,and 200 k Hz were subjected to second-stage amplification.The pulse output of the pulsed laser seed source after second-stage amplification was studied.Frequency,pulse width,pulse waveform and other pulse characteristics and spectral data,the causes of pulse width wideni ng and waveform change after secondary amplification are analyzed.5.Based on the acousto-optic Q-switching technology,all-fiber pulse laser experiment achieved a maximum single pulse energy of 8.36 m J,average laser output power up to 642 W.Using self-made fiber optic devices,acoustooptic Q-switched pulse fiber Laser with pulse repetition frequency of 100 k Hz and average power of 500 W was integrated and successfully used in laser cleaning.