Study On Laser Damage Properties Of Dielectric Films Prepared By Magnetron Sputtering

The optical thin films are important parts of the optical components. The optical components in laser and laser system play irreplaceable important roles. The optical components damage may result in the whole optical system function failure. At the same time, optical thin film component is the weakest link of laser system. For high power and high energy laser system, Laser film performance is always one bottleneck to a higher energy and higher power development. So the study of film laser damage characteristics, improving the film laser damage threshold, expanding their scientific research and daily application has an important practical value.TiO2and Al2O3thin films are deposited on K9galss substrates using the magnetron sputtering technology. The optimum process parameters of deposited TiO2and Al2O3thin films are obtained by using ellipsometer and spectrophotometer measure their optical characteristics. The experimental results show that the best parameters of magnetron sputtering TiO2thin film: sputtering current is8A, sputtering pressure is1.3Pa, ratio of oxygen and argon is1:1. The best parameters of magnetron sputtering Al2O3thin film:sputtering current is0.5A, sputtering pressure is2.0Pa, ratio of oxygen and argon is1:8. AR coating at1064nm is designed by optical thin film design method and optical thin film design software. This AR coating by deposited by By-700unbalance magnetron sputtering coating machine. The measured tranmissivity can reach99.5%at1064nm. The laser damage threshold of this AR coating is measured. The results show that the maximum laser damage of AR coating is4.3J/cm2. The maximum laser damage can reach5.1J/cm2after annealing process.