title: Combining wet etching and real-time damage event imaging to reveal the most dangerous laser damage initiator in fused silica.
abstract: A reliable method, combining a wet etch process and real-time damage event imaging during a raster scan laser damage test, has been developed to directly determine the most dangerous precursor inducing low-density laser damage at 355 nm in fused silica. It is revealed that ~16% of laser damage sites were initiated at the place of the scratches, ~49% initiated at the digs, and ~35% initiated at invisible defects. The morphologies of dangerous scratches and digs were compared with those of moderate ones. It is found that local sharp variation at the edge, twist, or inside of a subsurface defect is the most dangerous laser damage precursor.
authors.affiliation: Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Guohang
authors.initials: G
authors.lastname: Hu
authors.forename: Yuanan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Liu
authors.forename: Dawei
authors.initials: D
authors.lastname: Li
authors.forename: Qiling
authors.initials: Q
authors.lastname: Xiao
authors.forename: Kui
authors.initials: K
authors.lastname: Yi
authors.forename: Jianda
authors.initials: J
authors.lastname: Shao