Laser-induced damage of the optical coatings due to organic contamination in vacuum

Monolayer ZrO2 and multi-layer ZrO2/SiO2 films were contaminated deliberately with toluene in vacuum environments. Laser-induced damage tests were made on clean and contaminated ZrO2/SiO2 high reflective films. Surface adsorption layer model was presented to evaluate the impact of organic contaminations on the laser-induced damage. Based on this model, the distributions of electric field and temperature field in multi-layer ZrO2/SiO2 films were calculated. Results show that the mere organic contaminations cannot induce the thermal damage of optical films. The inter-coupling between defects and organic contaminations is probably attributed to the decrease of the laser-induced damage threshold in contaminated samples.