Temperature dependence of porous silica antireflective (AR) coating

Abstract

In this paper, the antireflective coatings consisting of porous silica particles from a silica sol are applied by dip method. The relationships among composition, viscosity and temperature have been studied. The coating homogeneity is opium for the laser wavelengths of 1064 nm, 532 nm and 355 nm. The peak transmission of coated BK-7 glass substrate is higher than 99.5%. The laser induced damage thresholds of the antireflective coatings were range of 7 - 10 J/cm2, for 1 ns pulse width and 1064 nm wavelength. These damage thresholds were suitable for our national ICF program. It is noted that the optical homogeneity of coating and the viscosity of coating sol were strongly influenced by the temperatures in the duration of sol ripening.