Fig. 1. Schematic diagram of experimental system

Fig. 2. Schematic diagram of torsion pendulum micro impulse measurement system

Fig. 3. Measurement system for mm-level or cm-level spot size

Fig. 4. Variation of spot size with the laser fluence when measuring the ablation impulse generated by irradiating Al 5A06 target

Fig. 5. The typical changes of torsion angle with time after the pulse laser was applied

Fig. 6. Preprocessing results of experimental data

Fig. 7. The impulse of the three metal materials irradiated at different laser fluences

Fig. 8. The impulse coupling coefficient of the three metal materials irradiated at different laser fluences

Fig. 9. The relationship between the transmittance and the laser fluence