Fig. 1. Generalization of coupled-wave equations to two-dimensional systems.

Fig. 2. Schematic of a dual-pass Nd: YLF laser amplification system.

Fig. 3. Beam shaping and spot acquisition subsystems: (a) beam shaping subsystem; (b) spot acquisition subsystem.

Fig. 4. Intensity-dependent SHG conversion efficiency in LBO crystal (red line: simulation; blue line: experiment).

Fig. 5. Comparative spatial-intensity distributions across beam reshaping stages: (a) regeneratively amplified beam post-expansion profile; (b) seed with spatial shaping; (c) amplified seed with spatial shaping.

Fig. 6. Beam profile evolution induced by SHG (red line: fundamental frequency spot; blue line: 527 nm spot at 0.51 GW/cm²).

Fig. 7. Schematic of the variation of spot spatial distribution at different fundamental frequency laser intensities (characterized by CV) (red line: curves of SHG conversion efficiency with fundamental laser density of LBO crystal; blue line: evolution of the CV values of the spot in the simulation).