Analysis and comparison of coating damage induced by laser at lms and lOns pulse-widths

In order to investigate the damage induced by ms laser,the experiment installation was established according to ISO-11254 and GB/T-16601.The 1064nm laser-induced damage thresholds of Ti2/Si2 coatings at lms and 10ns pulse-widths were studied,and the damage photos,damage depth,damage radius and damage mechanisms were also investigated.The damage of the coatings induced by ms laser was compared with that induced by ns laser.The damage threshold of energy density induced by ms laser is one order of magnitude higher than that of 10ns laser,and the damage threshold of power density induced by ms laser is one ten-thousandth of that of 10ns laser.The damage radius induced by ms laser is 180μm longer than that induced by ns laser,and the damage depth is 200μm deeper.It could be concluded that 1ms laser induced damage of optical coatings is more severe,it not only damage the coating but also destroy the substrate of the coating.The results provide important references for the researches of damage induced laser with pulse duration at millisecond scale.