Fig. 1. Preparing process of sol-gel antireflective coating by impregnation and drawing method

Fig. 2. Vacuum pollution experimental device

Fig. 3. Nanosecond laser damage testing platform

Fig. 4. SEM images of sample before and after contamination. (a) Before contamination; (b) after contamination

Fig. 5. Surface roughness analysis. (a) Comparison of sample surface roughness before and after contamination; (b) relationship between relative variation in surface roughness and surface mass density of organic contamination

Fig. 6. AFM images of coatings on sample surface. (a) Group 1, before contamination; (b) Group 1, after contamination; (c) Group 4, before contamination; (d) Group 4, after contamination

Fig. 7. Influence of organic contamination on transmittance of sol-gel antireflective coating on sample surface. (a) Group 1; (b) Group 2; (c) Group 3; (d) Group 4

Fig. 8. Relation between loss of transmittance and surface mass density of organic contamination

Fig. 9. Laser-induced damaged threshold (LIDT) analysis. (a) LIDT of sol-gel antireflective coating before and after contamination; (b) relationship between relative loss of LIDT and surface mass density of organic contamination

Fig. 10. Surface damage morphologies of sol-gel antireflective coating (F_th denotes laser-induced damage threshold)

Fig. 11. Damaged area of sample surface. (a) Group 1; (b) Group 2; (c) Group 3; (d) Group 4