激光对光学薄膜的损伤仍然是限制高能激光系统的主要挑战。对杂质诱导薄膜损伤的激励进行了研究: 首先对损伤形貌进行了观测, 在此基础上对杂质对薄膜的作用效应进行了分析。研究结果表明: 杂质粒子对薄膜产生的各种效应, 主要分为热力学效应、散射引起干涉效应和激光等离子体破坏效应, 这三种效应的共同作用效果决定了损伤的特点。这些作用效应与粒子的半径密切相关: 当粒子较小时, 激光的沉积量较少, 引起邻近材料的温升较低, 扩散范围较小, 主要是熔化破坏; 当粒子较大时, 激光沉积量较多, 会引起邻近光学材料的汽化和电离, 形成激光等离子体而造成大的烧蚀坑。

Laser-induced damage in optical film remains a great challenge in high power laser systems. The mechanism of inclusion damage to film had been studied: firstly, the film damage morphologies had been observed and then the effects of inclusions on film had been analyzed. The research results show that the damage effects of inclusions on film can be divided into thermodynamic effects, interference effects due to scattering and laser plasma effects, the combined action of those damage effects determine the characteristics of damage points. The effects above are closely related to the particles radius: for smaller radius, the deposited laser energy is less and temperature is lower, as the heat diffusion range is smaller and damage points are mainly due to the melting. While for larger radius, the energy deposition and temperature are higher, and the laser plasma can be formed easily and cause big ablated pits.