Fig. 1. 60 W nanosecond single-frequency slab green laser (for detailed information, see Refs. [12,13]).

Fig. 2. a, Beam quality and, b, pulse width for 60 W nanosecond single-frequency slab green laser.

Fig. 3. Space debris detected in 2017.

Fig. 4. Space debris laser ranging: a, range precision change with RCS and, b, range precision change with the size RCS of space debris.

Fig. 5. Space debris laser ranging: a, smallest RCS, 0.25m2 (ID37831), and, b, best ranging precision, 13.68 cm (ID04657).

Fig. 6. Farthest measurement range of space debris RCS analysis.

Fig. 7. Space debris characteristics: a, spin (ID14700) and, b, two reflective surfaces (ID25263).