激光场强分布对类金刚石薄膜激光损伤阈值的影响

摘要

采用非平衡磁控溅射技术,在双面抛光的硅基底上沉积了DLC薄膜,基于ISO11254-1损伤测试平台对DLC薄膜进行了损伤阈值测试；计算了DLC薄膜激光场强及温度场分布,对比了激光场强与损伤阚值的关系.计算结果显示:薄膜表面激光场强增大,DLC薄膜的激光损伤阚值变低；激光场强相等时,随着薄膜厚度增加,激光损伤阚值变小.分析认为:薄膜表面激光场强增大后,激光与DLC薄膜相互作用,产生的等离子体加剧薄膜对激光能量的吸收并产生热累积,激光场强诱导sp3杂化向sp2杂化转变,致使DLC薄膜发生石墨化,从而影响了DLC薄膜的激光损伤阈值.%The un-balanced magnetron sputtering (UBMS) is used to deposit the diamond-like carbon . (DLC) film. Based on ISO11254-1 damage testing platform, its laser-induced damage threshold (LJDT) is tested. Then the distribution of its laser and temperature field are calculated. The relationship between laser field and LJDT is contrasted. The calculated results indicate that when the laser on the film surface is intensified, the DLC film' s LJDT decreases. When the laser field remains unchanged, the DLC film' s LJDT decreases as it thickens. It is considered through the analysis that when the laser field is intensified on the film surface, the plasma produced in the interaction between the laser field and DLC film will catalyze the film' s heat absorption and accumulation from the laser. At this time, the laser field is inducting sp3to sp2and this causes the graphitization of DLC film whose LJDT is finally altered.