A new silica antireflective coating with improved hydrophobicity and optical stability in a vacuum is obtained by a two-step route. Firstly, silica sols are prepared with a sol-gel process, in which tetraethyl orthosilicate is utilized as a precursor. And by introduction of fluorine containing glycol into the sols, the porosity of silica particles and surface polarity of the coatings are decreased. Afterward, coatings are constructed with low surface roughness by modification of PMBA-PMMA. The coatings retain transmission of up to 99.6%, and laser damage threshold of about 50 J/cm2 at a wavelength of 532 nm (1-on-1, 10 ns).
© 2014 Chinese Optics Letters
Qinghua Zhang, Lian Zhou, Wei Yang, Haohao Hui, Jian Wang, and Qiao Xu, "Sol-gel preparation of a silica antireflective coating with enhanced hydrophobicity and optical stability in vacuum," Chin. Opt. Lett. 12, 071601- (2014)