Mitigating Scratches in Manufacturing Process to Strengthen the Resistance of Fused Silica to Laser Damage
Scratches generated in polishing are deleterious to precision optics because they can obscure and modulate incident laser light, which will increase the probability of laser damage to optical components.We here employed ultrasonics/megasonics assisted HF etching to alleviate the damage precursors.Samples were treated by being submerged into 6%wt.HF solution under various conditions, i.e.without acoustic power and with acoustic power at different power density, to etch various material away from fused silica surfaces.The evolution of scratch morphologies was monitored and damage performance was tested against the surfaces without brittle scratches (control samples).The results show that the scratches can be enlarged and the microcracks can be opened and blunted by means of wet chemical etching.20~25μm material removal is sufficient to remove the lateral cracks that accompany the brittle scratches in our experiments.It is shown that wet chemical etching can increase the laser induced damage threshold (LIDT) at the scratches up to a factor of 1.77 while the addition of acoustics (~0.6W/cm2 and/or ~2W/cm2) has marginal effects on the LIDT.
Polishing Grinding Chemical Impurities Mechanical Cracks Scratches Laser-Induced Damage Threshold
Yaguo Li Hui Ye Qinghua Zhang Zhigang Yuan Jian Wang
Fine Optical Engineering Research Centre, Chengdu 610041, China School of Mechanical Engineering, University of Shanghai for Science & Technology, Shanghai 200093,
国际会议
上海
英文
149-155
2017-11-19（万方平台首次上网日期，不代表论文的发表时间）