Influence of laser passivation on fused silica damage after CO2 laser mitigation
激光钝化对熔石英修复后损伤性能影响的实验研究

A 10.6μm CO2 big size laser beam is used to passivate the ablation deposit on surface of damage site which is repaired with single laser pulse.When the irradiated region is placed on front surface,modulation by 355 nm UV ns laser pulse is inhibited effectively; when the irradiated region is situated on rear surface,the initial damage threshold exceeds the substrate initial damage threshold. Second repair makes the thermal stress distribution enlarged obviously and the thermal stress magnitude weakened.The damage growth examination shows that once thermal stress is released,the initial phase damage growth exhibits an exponential tendency and as shoot number increases the damage size approaches to a constant value.