Fig. 1. Optical path design of regenerative amplifier

Fig. 2. Output spectrum curve of oscillator

Fig. 3. Transmission curve of SSF^［24］

Fig. 4. Schematic diagram of dual-channel pulse cleaning device

Fig. 5. When SSF is added to the cavity，the energy stability of the pump pulse and the energy stability of the amplified light after passing through the dual-channel pre-pulse cleaning device

Fig. 6. Pre-pulse intensity curve before and after passing through the dual-channel pre-pulse cleaning device

Fig. 7. When SSF is added to the cavity，the final spectrum curve and spectrum phase of amplification and interference autocorrelation trace of the pulses after the compressor

Fig. 8. When the SSF is placed in the amplifier cavity，the track of the third-order autocorrelation

Fig. 9. When SSF is applied outside the cavity，the final spectrum curve and spectrum phase of amplification and interference autocorrelation trace of the pulses after the compressor

Fig. 10. Pulse energy stability of amplified light after passing through dual-channel pre-pulse cleaning device when SSF is applied outside the cavity

Fig. 11. When the SSF is placed inside and outside the amplifier cavity，the trajectory of third-order autocorrelation

Fig. 12. The actual transmission curve of the SSF and the spectrum of the ASE in the ring cavity without SSF