Deposition of SiO2 films with high laser damage thresholds by ion-assistedelectron-beam evaporation

SiO2, thin films (approximate to 100 nm thick) with transmittivity and a la ser damage threshold nearly equal to those of bulk material are deposited o n silica substrates by the technique of ion-assisted electron-beam evaporat ion. The influence of film packing density on the laser damage threshold is investigated by the technique of photoacoustic probe beam deflection. It i s shown that films with lower packing density may have a higher laser damag e threshold and as a consequence better heat dissipation. (C) 1999 Optical Society of America. OCIS codes: 140.3330, 310.1860, 310.6860.