Laser-Induced Thermal Damage Simulations of Optical Coatings Due to Intercoupling of Defect and Organic Contamination

Abstract

The coupling model of defect and organic contamination was presented to analyze the coupling effects on laser-induced damage and understand the damage degradation mechanism of optical films in a closed vacuum environment. The distributions of temperature rise around an absorbing defect in multilayer ZrO 2 /SiO 2 films were computed based on the finite-element simulation. Laser induced damage tests were made to compare with the theoretical model. Test results were in an agreement with the presented model and calculated results of a temperature rise.

Light Field Intensification in Optical Films Induced by Intercoupling of Defects and Organic Contamination

“…Therefore, the decreasing laser-induced damage threshold of optical films used in vacuum is not attributed to the intercoupling effects between the defect and the organic contamination layer. This result is in accordance with our previous conclusions [ 10 , 12 ].…”

“…Therefore, organic contamination droplets adsorbed on the surface of a film will cause further local light field enhancement, in contrast to a clean film, which in turn intensifies the laser damage of the film. This result is also in agreement with the experimental data reported in the literature [ 10 ].…”

“…intensifies the laser damage of the film. This result is also in agreement with the experimental data reported in the literature [10].…”

“…It can be seen that the different thicknesses of the organic Therefore, organic contamination droplets adsorbed on the surface of a film will cause further local light field enhancement, in contrast to a clean film, which in turn intensifies the laser damage of the film. This result is also in agreement with the experimental data reported in the literature [10]. Figure 5 shows the coupling effect of a defect and an organic contamination layer on the local light field of a TiO 2 optical film when the thickness of the organic contamination layer is 20, 40, 60, 80, and 100 nm.…”

“…It is believed that nano-defects caused by the fabrication of optical thin films are a potential source and they can significantly affect the laser damage susceptibility. Studies have also shown that the coupling effects of defects and organic contamination induce severe laser-induced thermal damage [ 10 , 11 , 12 , 13 ]. The laser damage process is the result of the coupling of multi-physical fields, and local light field intensification is the primary and first process and the premise of subsequent damage.…”