Preparation of contamination-resistant ultraviolet broadband double-layer antireflective coating

Abstract A double-layer broadband antireflection (AR) coating with excellent transmittance at 250–400 nm has been designed and prepared by the sol-gel method. The quarter-half double-layer structure is optimized with the aid of Filmstar thin film design software. Mesoporous SiO₂ film templated by an ethylene oxide-propylene oxide-ethylene oxide triblock copolymer is used as the top layer, and a ZrO₂-SiO₂ hybrid film with matching refractive index is employed as the bottom layer. 1H, 1H, 2H, 2H-Perfluorodecyltriethoxysilane is used to modify the surface of the AR coating, which greatly improves the environmental stability of the coating. The obtained double-layer AR coating can achieve an average transmittance of 99.34% in the wavelength range of 250–400 nm. The laser induced damage threshold of the coating is measured using a 355 nm laser (pulse width: 6.4 ns), and the results show that the damage threshold is 2.24 J·cm⁻ ². This study provides a new way for the preparation of UV AR coatings with good optical performance and environmental stability.