We successfully presented a multi-pulse picosecond laser with passively mode-locking, grating-stretching, regenerative amplifier and grating compression technologies. Firstly, 8.5 ps pulses with a repetition rate of 143 MHz and a maximum average output power of 160 mW were obtained by a semiconductor saturable absorption mirror (SESAM). Secondly, we got the pulses width stretched to 99.9 ps with 90 mW and single grating. Thirdly, a pulse sequence with each of five pulses per group was obtained by using a multi-pulse regeneration amplifier system, from which output energy was about 28 mJ at the repetition rate of 1 kHz and 112.1 ps in single pulse width. Finally, using a grating compressor we acquired these pulses compressed to a pulse width of 28 ps and 14 mJ in each group at a repetition rate of 1 kHz.
- Regeneration amplifier