Mechanism initiated by nanoabsorber for UV nanosecond-pulse-driven damage of dielectric coatings.
A model of plasma formation for UV nanosecond pulse-laser interaction with SiO(2) thin film based on nanoabsorber is proposed. The formalism considered the temperature dependence of band gap. The numerical results show that during the process of nanosecond pulsed-laser interaction with SiO(2) films, foreign inclusion absorbing a fraction of incident radiation heats the surrounding host material through heat conduction causing the decrease of the band gap and making the initial transparent matrix into an absorptive medium around the inclusion. During the remainder pulse, the abosorbing volume of the host material is effectively growed and lead to the formation of the damage craters. We investigated the experimental damage craters and compared with theoretical prediction. The pulselength dependence of damage threshold was also investigated.
Wei
Chaoyang
C
R&D Center For Optical Thin Film Coatings, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, PR China. Siomwei@mail.siom.ac.cn
Shao
Jianda
J
He
Hongbo
H
Yi
Kui
K
Fan
Zhengxiu
Z
D003198:Computer Simulation; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects* / Q000648:ultrastructure; D012822:Silicon Dioxide / Q000737:chemistry* / Q000528:radiation effects*; D013499:Surface Properties / Q000528:radiation effects; D014466:Ultraviolet Rays
D012822:Silicon Dioxide