Research On Nanosecond Pulse Yb³⁺-doped Fiber Laser

This paper mainly studies the basic working principle, structure and output characteristics of the nanosecond pulse ytterbium doped fiber laser, the laser amplification technology, and Q-switching technology, and respectively takes the acousto-optically Q-switched fiber laser and the Q-switched solid state laser as seed sources. It uses laser amplification technology to amplify the nanosecond pulse fiber laser, measures the power and the pulse waveform of the amplifier with different output, and optimizes various parameters of the laser.Acousto-optically Q-switched is used to obtain the nanosecond pulse. At the same time,the modulation frequency is 20 to 60 k Hz, and the center wavelength is 1064.19 nm. When the repetition frequency is set as 20 k Hz, the pulse width is 77 ns, the maximum output power is 26.19 W, and the peak power of the nanosecond pulse is 17.0k W correspondingly; when the repetition frequency changes into 60 k Hz, the maximum output power becomes 28.10 W,the pulse width turns into 163 ns, and the peak power is 2.9k W correspondingly. Namely, the pulse peak power gradually reduces with the increase of repetition frequency. The passively is utilized to get the nanosecond pulse seed. In the meantime, the repetition frequency is 71.4k Hz. When the pump power the fiber amplifier is 5.2 W, the output power becomes 2.78 W,the slope efficiency corresponds to 53.8%, and the peak power changes to 15.15 k W.