离子束倾斜入射抛光对表面粗糙度的影响

基于光学元件离子束高精度确定性抛光技术,在自行研制的离子束抛光机床上,本文研究了离子束倾斜入射抛光对光学材料熔石英表面粗糙度的影响.为了在离子束抛光中改善表面粗糙度,采用了0°～80°之间不同入射角度的离子束倾斜抛光和倾斜45°入射均匀去除两种实验方案进行研究,其中不同入射角度抛光实验研究结果表明:离子束垂直入射抛光较难改善表面粗糙度,倾斜入射抛光可以较好地改善表面粗糙度,入射角为30°～60°之间时抛光效果最佳,表面粗糙度得到明显改善；倾斜45°入射均匀去除抛光实验结果表明表面粗糙度的RMS值由抛光前(0.92±0.06)nm下降到(0.48±0.04)nm,提高了光学零件的表面质量,验证了离子束倾斜入射抛光可以较好地改善表面粗糙度,实现了离子束倾斜抛光超光滑表面的生成.

Impact of Oblique Incidence in Ion Beam Figuring on Surface Roughness

Based on the self-developed high-precision and deterministic ion beam figuring（IBF）,the paper researched the impact of oblique incidence in IBF on the surface roughness of a typical optical material fused silica.To improve the surface roughness in the polishing process of IBF,two experiments were conducted,one with the polishing at 0°—80° different angles and the other with uniform removal under the oblique incidence angle 45°.The result of the former experiment shows that surface roughness will not be advanced under perpendicular incidence but can be improved at oblique incidence.At the incidence angle between 30°—60°,surface roughness is obviously improved.The result of the latter one shows that RMS of surface roughness is reduced from（0 92±0 06） nm to（0 48±0 04） nm after polishing and that the surface quality of optical parts is improved.Under oblique incidence,the IBF can commendably improve surface roughness and achieve an ultra-smooth surface.