Resistance of Scratched Fused Silica Surface to UV Laser Induced Damage

Evolution of oxygen deficiency centers (ODCs) on a fused silica surface irradiated using a 355 nm ultraviolet (UV) laser beam in both vacuum and atmospheric conditions was quantitatively studied using photoluminescence and X-ray photoelectron spectroscopy. When the fusedsilica surface was exposed to the UV laser in vacuum, the laser damage threshold was decreased whereas the concentration of the ODCs was increased. For the fuse silica operated under the high power lasers, creation of ODCs on their surface resulted from the UV laser irradiation, and this is more severe in a high vacuum. The laser fluence and/or laser intensity have significant effects on the increase of the ODCs concentration. The ODCs can be effectively repaired using postoxygen plasma treatment and UV laser irradiation in an excessive oxygen environment. Results also demonstrated that the “gain” and “loss” of oxygen at the silica surface is a reversible and dynamic process.

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Explosion plume on the exit surface of fused silica during UV laser- induced damage

Results in Physics ◽

10.1016/j.rinp.2021.105094 ◽

2022 ◽

Vol 32 ◽

pp. 105094

Author(s):

Chengyu Zhu ◽

Lingxi Liang ◽

Ge Peng ◽

Hang Yuan ◽

Luoxian Zhou ◽

...

Keyword(s):

Fused Silica ◽

Uv Laser ◽

Exit Surface ◽

Laser Induced Damage

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Effects of Ion Beam Etching on the Nanoscale Damage Precursor Evolution of Fused Silica

Materials ◽

10.3390/ma13061294 ◽

2020 ◽

Vol 13 (6) ◽

pp. 1294

Author(s):

Yaoyu Zhong ◽

Yifan Dai ◽

Feng Shi ◽

Ci Song ◽

Ye Tian ◽

...

Keyword(s):

Silica Surface ◽

Ion Beam ◽

Damage Threshold ◽

Fused Silica ◽

Structural Defects ◽

Laser Damage ◽

Material Structure ◽

Ion Beam Etching ◽

Damage Resistance ◽

Laser Induced Damage

Nanoscale laser damage precursors generated from fabrication have emerged as a new bottleneck that limits the laser damage resistance improvement of fused silica optics. In this paper, ion beam etching (IBE) technology is performed to investigate the evolutions of some nanoscale damage precursors (such as contamination and chemical structural defects) in different ion beam etched depths. Surface material structure analyses and laser damage resistance measurements are conducted. The results reveal that IBE has an evident cleaning effect on surfaces. Impurity contamination beneath the polishing redeposition layer can be mitigated through IBE. Chemical structural defects can be significantly reduced, and surface densification is weakened after IBE without damaging the precision of the fused silica surface. The photothermal absorption on the fused silica surface can be decreased by 41.2%, and the laser-induced damage threshold can be raised by 15.2% after IBE at 250 nm. This work serves as an important reference for characterizing nanoscale damage precursors and using IBE technology to increase the laser damage resistance of fused silica optics.

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