Study On Ion Beam Polishing Technology Of Fused Quartz Surface

With the rapid development of optical technology,high-performance optical systems are widely used in national defense,civil and biomedical fields,and the demand for precision optical components is increasing.As the key technical means to obtain ultra-smooth surface,ion beam polishing has non-contact processing characteristics with the surface of the component,which can avoid the edge effect and surface damage caused by other mechanical polishing.In addition,it can achieve atomic level material removal and obtain an ultrasmooth surface.Based on sputtering theory,the influence of ion energy and incident angle on sputtering yield is simulated by SRIM software,and the stability of ion source is studied by Faraday scanning method.The stability of the rotating Gauss removal function in ion beam polishing is evaluated from the point of view of peak removal rate,volume removal rate and half full width.Based on Taguchi method,orthogonal experiments are designed to determine the optimal parameter combination,and the optical components are processed by iterative experiments.The ability of ion beam polishing to improve the surface morphology of optical elements is confirmed by non-contact interferometer testing and data analysis.The rapid convergence of surface PV value could be achieved,but the surface roughness has increased.In order to reduce the surface roughness,a thin film with a certain thickness was deposited on the base surface by ion beam sputtering.In the process of optimizing and improving the process,the uniformity of thin films deposited by ion beam sputtering was studied.The uniformity of thin films on the surface of optical elements was improved by optimizing the residence time of ion beam at different positions on the sample surface.The deposition rate was calculated and analyzed,and the effect of deposition rate on the surface quality of coated components was studied.The surface quality of optical components was further improved by ion beam sputtering deposition process.The final surface roughness is 0.34 nm lower than the original value of the fused silica optical element,which effectively improves the surface quality of the fused silica optical element.