The damage mechanisms of fused silica irradiated by 355 nm laser in vacuum

After pre-irradiation in 10−5 Torr vacuum, the 355 nm laser-induced damage threshold of fused silica decreased, while in air the damage resistance performance increased. The structure and defects of fused silica has been studied by means of Fourier transform infrared, Raman and Photoluminescence spectroscopy. The damage mechanisms are discussed.