Damage behaviors of silica microparticles on fused silica optics under 355 nm high fluence laser

Particulate contaminants are common damage precursors on optics in the daily operation of high laser power systems. In this paper, the damage behaviors of silica particles attached to the front and back surfaces of fused silica optics under the irradiation of a 355 nm laser were studied. Results showed that silica particles on the front surface tend to splash severely under high fluence, while the particle on the back surface forms a large laser-induced shallow pit (LSP)-like pit on the substrate. Different damage morphologies were observed, and damage mechanisms were also proposed.