Preparation of sol-gel ZrO_2-SiO_2 highly reflective multilayer films and laser-induced damage threshold characteristic

摘要

Sol-gel (ZrO_2/SiO_2)~(12) ZrO_2 films were prepared by spin coating method. The reflectivity spectrum of the films was measured with a Lambda 900 spectrometer. In order to investigate laser-induced damage threshold (LIDT) characteristic of highly reflective films, one-layer ZrO_2 and SiO_2 films, two-layer ZrO _2/SiO_2 and SiO_2/ZrO_2 films were also prepared by spin coating method. LIDT of each film was measured. Damage morphology after laser irradiation was characterized by optical microscopy (Nikon E600K). The experimental results showed that the reflectivity of (ZrO_2/SiO_2)~(12) ZrO_2 film at 1064 nm and 355 nm wavelength is 99.7%. The LIDT results decreases as the number of layer of films increases. All the films have similar damage morphology. The experimental results are explained by the different temperature profiles of the films.