Fig. 1. Schematic of high power nanosecond pulsed ytterbium-doped fiber laser

Fig. 2. Variation of output pulse width with the pumping power

Fig. 3. Output pulse waveform of the active Q-switching oscillator

Fig. 4. Output pulse sequence of active Q-switched oscillator

Fig. 5. Variation of output power of main power amplifier with the increase of incident pumping power

Fig. 6. Output pulse waveform of the main power amplifier at the maximum output power

Fig. 7. Spectrum of the main power amplifier at the maximum output power

Fig. 8. Experimental device for laser rust removal

Fig. 9. Laser rust removal results at different pulse powers. (a) 100 W; (b) 300 W