1064nm nanosecond laser induced ring structure on SiO2 films with different thickness in air and vacuum environments

摘要

The ring structure induced by 1064 nm nanosecond laser on SiO2 films with different film thickness was investigated in air and vacuum environments. The damage depth and ring spacing versus the incident laser flux were analyzed. It is found that vacuum induced high defect density as a result of low defect damage threshold, compared with the air environment. And for the same laser fluence, the ring spacing was reduced while the damage depth was increased once the surrounding air was removed. Our research results also indicate that the defects logging in subsurface of coating layer, play a much more crucial role in the formation process of laser-induced ring structures.