Study of the effects of stress wave behavior in laser-induced exit-surface damage of fused silica using time-resolved multi-polariscopic imaging

During laser-induced exit-surface damage of fused silica components, strain and stress are generated and accompanied by cracks in the substrate, further deteriorating the component. The authors studied the behaviors of surface and shear waves quantitatively using a time-resolved multipolariscopic imaging system, showing their potential to affect the development of circumferential and longitudinal cracks. When the material received a cumulative shot, a greater stress intensity was observed, and the stress wave had a greater impact on the laser-induced damage. The results indicate that the two stress waves from the cumulated shots dominated the developmental characteristics of the damage morphology.