光学表面粒子污染物散射的单层薄膜调控特性  

Single-layer film regulation characteristics of particle pollutant scattering from optical surfaces

作　　者：杨伟荣 潘永强[1] 郑志奇 Yang Weirong;Pan Yongqiang;Zheng Zhiqi(School of Photoelectric Engineering,Xi'an Technological University,Xi'an 710021,China)

机构地区：[1]西安工业大学光电工程学院,陕西西安710021

出　　处：《红外与激光工程》2021年第12期455-461,共7页Infrared and Laser Engineering

基　　金：陕西省教育厅重点实验室科研计划项目(18JS054);陕西省自然科学基础研究计划项目(2018JM6031)。

摘　　要：为了降低超精密低损耗光学元件表面粒子污染物的光散射损耗,文中提出通过在光学表面沉积单层薄膜来调控表面场强分布,从而降低散射损耗的方法。理论分析了K9玻璃超光滑光学表面不同厚度单层二氧化硅(SiO_(2))和单层二氧化钛(TiO_(2))薄膜表面上方半径为100 nm粒子污染物所在处的电场强度,理论分析结果发现,当SiO_(2)薄膜厚度为137.4 nm,TiO_(2)薄膜厚度为12.3 nm时,表面粒子污染物所在处的电场强度最小。在此基础上分别计算了光学元件表面沉积厚度为137.4 nm的单层SiO_(2)薄膜以及厚度为12.3 nm的单层TiO_(2)薄膜,表面粒子污染物的总散射损耗(S)和双向反射分布函数(BRDF),计算结果表明,在波长为632.8 nm的光垂直入射时,单层SiO_(2)薄膜和单层TiO_(2)薄膜可有效降低其表面粒子的BRDF,且可将K9玻璃表面的总散射分别降低12.40%和25.04%。实验验证了单层SiO_(2)薄膜对于表面粒子污染物散射降低的有效性。In order to reduce the light scattering loss of particle pollutants on the surface of ultra-precision lowloss optical elements, a method of adjusting the surface field intensity distribution by depositing a monolayer film on the optical surface was proposed. The electric field intensity of particle pollutants with a radius of 100 nm above the surface of monolayer SiO_(2)and monolayer TiO_(2)thin films of different thicknesses on the ultra-smooth optical surface of K9 glass was theoretically analyzed. The theoretical analysis results show that when the thickness of SiO_(2)thin film is 137.4 nm and the thickness of TiO_(2)thin film is 12.3 nm, the surface particle contaminant has the lowest electric field intensity. On this basis, the total scattering loss(S) and bidirectional reflection distribution function(BRDF) of particle pollutants on the surface of optical element, films for SiO_(2)with a thickness of 137.4 nm and TiO_(2)with a thickness of 12.3 nm were calculated respectively. The calculated results show that when the light with a wavelength of 632.8 nm is vertically incident, monolayer SiO_(2)film and monolayer TiO_(2)film can effectively reduce the BRDF of the surface particles, and the total scattering on the surface of K9 glass can be reduced by 12.40% and 25.04% respectively. The effectiveness of single-layer SiO_(2)thin film for reducing the scattering of surface particle pollutants is verified by experiments.

关 键 词：光学薄膜 光散射 双向反射分布函数(BRDF) 总散射损耗 

分 类 号：O484[理学—固体物理]