短波段光学减反膜的溶胶-凝胶法制备及性能分析

 随着大型激光器的发展，对短波段减反膜的要求日益提高，其中钕玻璃激光三倍频（355nm）的减反射成为新的技术要点。采用溶胶-凝胶工艺合成SiO₂溶胶，采用提拉镀膜法制备纳米多孔SiO₂薄膜，薄膜厚度为75nm，折射率控制在1.22，镀制在石英基底上的薄膜其355nm波长的反射率仅为0.2%。通过氨处理工艺和薄膜的表面修饰，薄膜的抗磨擦性能和疏水性能大大提高，薄膜经过蘸有灰尘、乙醇的棉花球擦洗20次和50次后，透射率最大值仅分别降低0.13% 和 0.39%，与水珠的接触角达到110°。

Preparation of hydrophobic-shortwave-band antireflective film by Sol-Gel process and its performance analysis

With the development of large-scale high power laser system,large size shortwave-band(such as 355nm)antireflective coatings are needed. In this paper,the Sol-Gel deriving SiO2 nano-structure shortwave-band antireflective coatings were prepared. Ellipsometer,FTIR,UV-Vis-VIR spectrometer and AFM were used to characterize the properties of the films. The refractive index of the film is about 1.22,and the thickness is 75nm. The reflectance of the film(on silica substrate)at 355nm is reduced to 0.2%. The scratch-resistant property of film was improved obviously after ammonia treatment,the maximum transmission values of the film are only reoluced 0.13% and 0.39% after 20 and 50 times scratch by the tampon with dirty. After surface modification the hydrophobicity of the film is improved and the contact angle is about 110°.