超光滑光学元件表面在真空环境下的污染物沉积特性研究  

Study on Contamination Deposition Characteristics of Ultra-Smooth Optical Component Surface in Vacuum Environment

作　　者：鲍浪 李定 车驰骋[1] 李钱陶[1] 王强 郭岩龙 王保峰 BAO Lang;LI Ding;CHE Chi-cheng;Li Qian-tao;WANG Qiang;GUO Yan-long;WANG Bao-feng(Huazhong Institude of Electro-Optics-Wuhan National Laboratory for Optoelectronics,Wuhan 430223,China)

机构地区：[1]华中光电技术研究所—武汉光电国家研究中心,湖北武汉430223

出　　处：《光学与光电技术》2022年第3期77-82,共6页Optics & Optoelectronic Technology

摘　　要：在高能、高功率激光系统光路中的超光滑光学元件上的高反射薄膜表面出现污染时,会导致光学元件的损伤,激光透过率下降,影响激光传输质量,并降低光学元件的损伤阈值,制约系统的负载能力和高通量稳定运行能力。为了尽可能减少元件表面污染物的沉积,对污染物沉积特性进行研究显得尤为重要。对密闭玻璃腔中超光滑元件表面的污染物沉积特性进行了研究,利用原子力显微镜和傅里叶红外光谱仪对不同手段处理后的样品进行测试和分析,实验结果表明,随着放置时间的增加,表面污染物的沉积越来越多。这种污染物中可能含有—NH化学键,会引起超光滑元件表面粗糙度的变化,可以使用酒精、丙酮或铬酸清洗,或者氧气氛围中等离子体放电等手段有效去除,但高温烘烤对污染物的消除没有明显的效果。根据上述实验结果,结合光学元件加工流程的综合分析,认为造成零件表面污染的原因是光学元件加工过程中残留的物质,在真空环境下缓慢释放所致。因此,对于洁净度要求极高的超光滑光学原件,在加工过程中尽可能地使用容易被简单溶剂消除的辅料,并在完成加工后减少贮存时间,尽快进入清洗工序,可以有效提升光学元件洁净度。The laser transmission quality will be affected if the surface of ultra-smooth optical component of laser system is polluted.In order to reduce the contamination deposition,the study on characteristics of contaminant deposition on ultrasmooth optical surface is of great significance.In this paper,the samples treated by different means are tested by atomic force microscope and Fourier infrared spectrometer.The results show that the deposition of contamination is increasing with the increase of time.This kind of contaminant might contain-NH chemical bond,which will cause the change of roughness of the ultra-smooth optical surface,also,it can be effectively removed by cleaning with alcohol,acetone or chromic acid,or by means of plasma discharge in oxygen atmosphere.However,high temperature baking has no obvious effect on the elimination of contaminant.This result is considered that the possible cause of surface contamination on the ultra-smooth optical component in vacuum system is the slow release of the residual organics during the process of optical component processing.Therefore,for ultra smooth optical elements with extremely high cleanliness requirements,auxiliary materials that are easy to be eliminated by organic solvent are suggested to be used as much as possible during the processing process,and the storage time should be reduced after processing,which can effectively improve the cleanliness of optical elements.

关 键 词：真空环境 超光滑 污染物 有机物 表面粗糙度 

分 类 号：TH74[机械工程—光学工程]