基于光学薄膜元件的热力学理论, 建立了强激光连续辐照下薄膜元件的热分析模型, 分析了强激光辐照下不同种类的表面杂质诱导薄膜元件的热熔融损伤和热应力损伤的过程。统计了不同口径和不同表面洁净度等级的薄膜元件上可诱导薄膜元件热损伤的杂质数量, 定量分析了杂质诱导薄膜元件热损伤的总面积, 计算了薄膜元件上热损伤的面积超过总面积的3%时所需的曝露时间。研究结果表明, 在强激光连续辐照下, 尺寸处于一定范围内的杂质会诱导薄膜元件的热熔融损伤和热应力损伤, 热损伤的方式与杂质类型密切相关。薄膜元件的口径越大、表面洁净度等级越高, 处于可诱导薄膜元件热损伤尺寸范围内的杂质数量越多。单个杂质诱导薄膜元件热应力损伤的损伤点面积比热熔融损伤的更大。

Based on the thermodynamic theory of the optical thin-film components, the thermal analysis model of thin-film components irradiated continuously by a high-power laser is established and the processes of the melting damage and the thermal stress damage induced by different kinds of surface impurities are analyzed. The statistic number of impurities inducing thermal damages on thin-film components with different sizes and different surface cleanliness levels is shown and the total thermal damage area of thin-film components induced by impurities is analyzed quantitatively. The exposure time when the thermal damage area of thin-film components exceeds 3% of the total area is calculated as well. The research results show that, under the high-power laser continuous irradiation, the melting damage and the thermal stress damage on thin-film components can be induced by impurities with sizes within a certain range. The damage way is closely related to the impurity type. The larger the aperture and the higher the cleanliness level of thin-film components, the larger the number of impurities with sizes within a certain range where the thermal damages on thin-film components can be induced. Furthermore, the damage point area of the thermal stress damage induced by a single impurity is larger than that of the melting damage.