Fig. 1. Schematic of single-point-diamond fly-cutting of KDP crystal

Fig. 2. SEM images of typical surface defects generated in fly-cutting fabrication of KDP crystal. (a) Pits; (b) convex

Fig. 3. WLI images of typical surface defects generated in fly-cutting fabrication of KDP crystal. (a) Pits; (b) convex

Fig. 4. EDS analysis of convex defects on KDP surface. (a) Microscopic image of defects; (b) spectral diagram

Fig. 5. Formation process of surface defects of KDP crystal. (a) Pits; (b) convex

Fig. 6. Influence of feed rate on surface pit defects of KDP crystal

Fig. 7. Surface painting fly-cutting of KDP crystal. (a) Painted surface before processing; (b) microscopic image of processed surface

Fig. 8. Schematic of introduction of surface defects by processing with circular-edge cutting tool

Fig. 9. Schematic for measuring BDT depth and crack depth of KDP crystal

Fig. 10. Measured BDT depth of KDP crystal

Fig. 11. Comparison between crack depth Yc and h under different UCT

Fig. 12. AFM images of KDP crystal surfaces processed along different cutting directions. (a) 0° direction; (b) 45° direction

Fig. 13. Cutting tool used for suppressing convex defects on KDP surface. (a) 3D model; (b) photograph

Fig. 14. Morphologies of KDP crystal surfaces processed by cutting tools with different structures. (a) Circular-edge cutting tool; (b) structure-optimized cutting tool