磁流变抛光对熔石英激光损伤特性的影响

Effect of magnetorheological finishing on laser damage properties of fused silica

为进一步提升熔石英元件的激光损伤阈值,研究了氢氟酸(HF)动态酸刻蚀条件下磁流变抛光工艺对熔石英元件激光损伤特性的影响规律。首先,采用不同工艺制备熔石英元件,测量它们的表面粗糙度。然后,采用飞行时间-二次离子质谱法(OF-SIMS)检测磁流变加工前后熔石英元件中金属杂质元素的含量和深度;采用1-on-1方法测试激光损伤阈值,观测损伤形貌,并对损伤坑的形态进行统计。最后,分析了磁流变抛光工艺提升熔石英损伤阈值的原因。与未经磁流变处理的熔石英元件进行了对比,结果显示:磁流变抛光使熔石英元件的零概率激光损伤阈值提升了23.3%,金属杂质元素含量也显著降低,尤其是对熔石英激光损伤特性有重要影响的Ce元素被完全消除。得到的结果表明,磁流变抛光工艺能够被用作HF酸动态酸刻蚀的前道处理工艺。

To further increase the laser-induced damage threshold of the fused silica elements, the effect of Magnetorheological Finishing（MRF） technology on the laser damage properties of fused sili- ca elements was investigated under the condition of Hydrogen Fluoride（HF） acid dynamic etching process. Firstly, the fused silica samples were prepared by different processes and their surface rough- nesses were measured. Then, the contents and depths of metal impurity elements before and after MRF processing were measured by Time of Flight- Secondary Ion Mass Spectroscopy （TOF-SIMS）.＇ The damage threshold was measured by 1-on-1 test method, and the damage morphology was ob- served and statistically analyzed. Finally, the reasons of increasing the laser-induced damage threshold of the fused siiica by the MRF were analyzed. The experimental results were compared with that of the fused silica without the MRF. It shows that the MRF can increase the laser damage threshold of fused silica by 23.3%. Moreover, the content of metal impurity elements is significantly reduced, es-pecially the Ce element which has a significant impact on the laser damage performance of fused silica is completely eliminated. It concludes that the MRF process can be used as a pre-treatment process for HF acid dynamic etching process.