Fig. 1. Slab module structure

Fig. 2. Ultrasonic scanning of welding surfaces. (a) Before welding process improvement; (b) after welding process improvement

Fig. 3. Thermal gradient distribution of slab cross section

Fig. 4. Simulation results of pump homogenization. (a) Schematic of pump coupling structure; (b) simulation result of spot intensity distribution; spot intensity distributions in (c) x-axis and (d) y-axis directions

Fig. 5. Schematic of nanosecond slab laser amplifier device with high peak power and high repetition rate

Fig. 6. Appearances of whole machine . (a) Before improvement; (b) after improvement

Fig. 7. Output characteristics of nanosecond slab laser amplifier with high peak power and high repetition rate. (a) Relationship between pump power and output power with near-field spot shown in lower right inset and laser spectrum shown in upper left inset; (b) stability test result of highest output power

Fig. 8. Time domain characteristics of output laser. (a) Repetition rate of pulsed laser; (b) width of single pulse

Fig. 9. Far field distributions of beam. (a) Two-dimensional distribution of far-field beam intensity; (b) three-dimensional distribution of far-field beam intensity