In this paper. colloid-based highly reflective coatings consisting of alter
nating layers of quarterwave thick high- and low-refractive index component
s were deposited on glass substrates by a sol-gel spin-coating method. SiO2
was used as the low-refractive index component, and ZrO2 as the high-refra
ctive index material. The colloidal suspension of ZrO2, prepared by hydroth
ermal hydrolysis of ZrOCl2, contained monoclinic nanocrystalline ZrO2, with
an average particle size of 15 nm. A minimum transmittance of 1% near 1064
nm was obtained from a 20-layer SiO2-ZrO2/PVP multilayer film. The ZrO2 pa
rticles were deposited in an ethanolic suspension containing polyvinylpyrol
dione (PVP) as a binder. The maximum transmittance in the visible range was
about 85%. A 1-on-1 laser-induced damage threshold of 16 J/cm(2) for the 2
0-layer SiO2-ZrO2/PVP film was observed using a Q-switched Nd:YAG high powe
r laser at a wavelength of 1.06 mu m and with a pulse width of 2.5 ns. (C)
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