Hafnia and yttria films for optical applications were prepared by puls
ed laser ablation with oxygen ion bombardment of the growing films. Th
e influence of the laser and ion beam parameters on the refractive ind
ex and microstructure of the films was investigated. The optical quali
ty of the films with respect to absorption and laser damage was charac
terized at the Nd:YAG-laser wavelength by measuring the laterally reso
lved absorptivity and the laser damage thresholds. Both hafnia and ytt
ria films prepared at low ion energy and intensity (150 eV, 50 mu A/cm
(2)) were amorphous and had a high bulk-like refractive index and pack
ing density. At high ion energy and intensity (700 eV, 400 mu A/cm(2))
the films became polycrystalline with high refractive index and packi
ng density at relatively high growth rates above 10 to 20 nm/min or re
latively low refractive index and packing density at low growth rates.
Films with high laser damage threshold at 1.06 mu m wavelength could
only be prepared with strong oxygen bombardment. Highly reflective mul
tilayer systems of only one material with alternately high and low ref
ractive index were prepared by varying the parameters of oxygen ion bo
mbardment during deposition. Their reflectivity and laser damage thres
hold at 1.06 mu m as well as their microstructure were investigated.