Initiated damage of laser induced in fused silica at 1064nm and 532nm

The useful lifetime of a laser optic in high power laser system is limited by both laser-induced initiated damage and the subsequent growth. We have studied and measured the initiated damage morphology on fused silica surface in air at 1064nm and 532nm at nanosecond. Results demonstrate a significant dependence of the initiated damage morphology and size on the type, diameter and lodging depth of the surface defects. We will compare the initiated damage morphology for entrance- and exit-surface. Possible reasons for the observed initiated damage behavior are discussed.