ZrO2/SiO2 Two-Layer Antireflective Coatings by Sol-Gel Process

A kind of lambda/4-lambda/4 ZrO2/SiO2 two-layer antireflective (AR) coatings was developed by sol-gel dip-coating method with zirconium n-propoxide and tetraethoxysilane (TEOS) as the precursors. The ZrO2 sol was prepared from the solution containing zirconium n-propoxide, hydrochloric acid and acetylacetone in ethanol. The results indicate the stability of the ZrO2 sol. The transmission of ZrO2/SiO2 two-layer AR coatings was 99.41% on fused silica substrate at 351 nm and about 99.63% on the BK-7 glass substrate at 1053 nm. The root mean square (RMS) of surface roughness was 1.038 nm in ZrO2/SiO2 AR coatings. The laser induced damage thresholds (LIDTs) of ZrO2 coating was 19.6 J/cm(2) (1064 nm, 1 ns), and the LIDTs of ZrO2/SiO2 AR coatings was 16.8 J/cm(2) (1064 nm, 1 ns).