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TiO 2 films of different thickness were prepared with the additives of acetylacetone (ACAC) and diethanolamine (DEA), respectively. The results showed that not only the additives but also the film thickness affected the optical properties, surface roughness, absorption and laser-induced damage threshold (LIDT) of TiO 2 films. The LIDT of the film with DEA was higher than that with ACAC, which was attributed to the lower defect density. With the film thickness increase, the significant decrease in LIDT of the film with ACAC was mainly due to the reduced band gap. It indicated that the amount of ACAC or the film thickness should be reduced as much as possible for preparing high LIDT TiO 2 films. After laser damage, the films with ACAC showed cracks, whereas the films with DEA showed spalling. The difference between the damage morphologies was discussed in details. [ABSTRACT FROM AUTHOR]

In this study, Ta 2 O 5 sol was synthesized from TaCl 5 precursor, and its time dependence of the viscosity, particle size distribution and photoluminescence spectra were studied. Then, Ta 2 O 5 films were prepared using this sol and were succeeding annealed at different temperatures without carbonization and cracks. It was found that the films had good properties such as high transparency, small absorption and high laser-induced damage threshold (LIDT). The LIDT decreased with the increase of the annealing temperature probably due to the acetylacetone in the films. The laser-induced damage morphologies of the films after annealing were different. With the annealing temperature increase, the dominant factor of the laser-induced damage transformed gradually from the stress to the thermal. According to the LIDT and damage morphologies, a structure evolution model of the films annealed at different temperatures was proposed. [ABSTRACT FROM AUTHOR]

Ta 2 O 5 films deposited by ion beam sputtering were post-treated with different methods. The optical properties, microstructures, surface morphologies, absorption and laser-induced damage threshold (LIDT) at 1064 nm and 12 ns of the films were comparatively studied. Annealing conduced to larger changes of optical transmittance and surface morphologies whereas it led to smaller changes of absorption and LIDT than laser conditioning. As it was shown, all the three post-treatment methods in this study were beneficial to the laser damage resistance of the films, yet the details of the defect elimination caused by these methods were different. A defect evolution model was proposed, which revealed the different effects of post-treatment methods on the defect repair of the films. The highest LIDT achieved by the combination of annealing and laser conditioning was due to their complementary effect which resulted in the lowest defect density and the smallest defect size of the film. [ABSTRACT FROM AUTHOR]

Highlights: [•] High LIDT Ta2O5 films were prepared using TaCl5 as precursor. [•] We revealed the functions of H2O2 in the sol formation. [•] The high LIDT was attributed to the nearly free of defects. [Copyright &y& Elsevier]