Fig. 1. Optical principle diagram of multiple-pulse picosecond laser at kHz repetition rate

Fig. 2. Mode-locked laser output. (a) Spectral line width; (b) pulse width

Fig. 3. Pulse is splitted into four pulses (div: 5 ns)

Fig. 4. Waveforms of regenerative output pulse of four pulses. (a) Pulse output waveform (div: 1 ns); (b) pulse growth pulse (div: 20 ns)

Fig. 5. Double pulse output of first and fourth pulses

Fig. 6. Beam quality of multi-pulse two-module single-pass amplification

Fig. 7. Diagram of space debris laser ranging system at the Shanghai observatory of Chinese Academy of Science^[8]

Fig. 8. Cone-shaped beam of emission laser

Fig. 9. Laser echo data obtained by space debris laser ranging

Fig. 10. Data processing result of double-pulse echo in satellite laser ranging for Compassi3