Single-layer TiO(2) and multilayer TiO(2)-SiO(2) optical coatings prepared from colloidal suspensions

Single-layer coatings on fused silica substrates have been prepared from aqueous colloidal suspensions of titania at room temperature. These coatings were porous and had a refractive index of 1.9. Multilayer high reflectivity dielectric coatings were also prepared by laying down quarterwave thick alternating coats at room temperature of this titania with silica, prepared from a colloidal suspension of silica. Single-shot laser damage threshold measurements at 1064-nm wavelength with a pulse length of 1 ns were carried out for both the titania and titania-silica systems. These averaged 7.5 and 6.2 J/cm(2), respectively.