溶胶-凝胶SiO2酸性膜与碱性膜的激光损伤行为

Laser-induced damage of sol-gel silica acid and basic thin films

采用溶胶-凝胶技术分别在K9基片上镀制了光学厚度相近的单层SiO2酸性膜和碱性膜。测试了两类薄膜的激光损伤阈值;分别采用透射式光热透镜技术、椭偏仪、原子力显微镜、扫描电镜和光学显微镜研究了两类薄膜的热吸收、孔隙率、微观表面形貌、激光辐照前薄膜的杂质和缺陷状况以及激光辐照后薄膜的损伤形貌。实验结果表明:相对于碱性膜,酸性膜有更大的热吸收和更小的孔隙率,因此其激光损伤阈值较小;两类薄膜不同的损伤形貌与薄膜的热吸收系数与微观结构有关。

The sol-gel monolayer silica acid and basic thin films on K9 glass substrates were prepared wlth the dip method from acid and basic catalyzed silica sols, respectively. Both films have nearly similar optical thickness. The laser-induced damage thresholds（LIDT） of the two kinds of films were measured. Thermal absorption, porous ratio and surface morphologies of films were investigated by Stanford photo-thermal solutions, ellipsometer, atomic force microscope（AFM） and scanning electron microseope（SEM）, respectively. Optical mieroseope was used to characterize the defects and impurities of films before laser irradiation and damage morphology after laser irradiation. The experimental results showed that compared with basic film, the silica acid film had larger absorption, smaller porous ratio, and smaller LIDT. Different damage morphologies of films were relative to their different absorption and microstruetures.