重复频率长脉冲激光辐照双层增透膜产生的热力损伤数值模拟研究

发布时间：2018-05-27 16:28

本文选题：重复频率激光 + 环向拉力损伤　；参考：《长春理工大学》2015年硕士论文

【摘要】：激光与物质间的相互作用研究在材料加工、机械制造业、光电成像系统等有着重要意义。而关于光学增透薄膜与重复频率激光的相互作用研究尤为重要,本文主要对重复频率长脉冲激光辐照光学薄膜材料的热力损伤情况进行数值模拟并分析其损伤情况。本文研究并建立了重复频率长脉冲激光分别辐照单层薄膜材料(Al2O3/K9)和双层薄膜材料(SiO2/Al2O3/K9)的物理模型,采用有限元算法求解相应的热传导方程和热应力方程,得到了材料内部热、力场分布。数值模拟结果表明,单层薄膜材料:当温度冷却时,残余环向热应力沿径向移动,在频率比较低时,基底首先发生热应力损伤,接着薄膜发生热应力损伤。双层薄膜材料:从激光参数上分析,在入射激光占空比相同的条件下,薄膜体系的温升随着脉宽的增大而减小;从整个薄膜体系中的热力损伤上分析,在时间顺序上SiO2膜层首先发生环向拉力损伤现象,然后K9基底发生环向拉力损伤,接着K9基底发生热熔融现象,最后SiO2膜层发生热熔融现象。本文结果可用于系统分析和揭示激光与光学薄膜相互作用机理,也可为光学薄膜设计及薄膜抗激光加固技术提供一定的理论参考和依据。
[Abstract]:The study of laser-matter interaction is of great significance in material processing, mechanical manufacturing, photoelectric imaging system and so on. It is very important to study the interaction between optical antireflection film and repetition rate laser. In this paper, thermal damage of optical thin film irradiated by long pulse laser at repetition rate is numerically simulated and its damage is analyzed. In this paper, the physical models of Al _ 2O _ 3 / K _ 9 and Si _ 2O _ 2 / Al _ 2O _ 3 / K _ 9) were studied and established, respectively. The corresponding heat conduction equation and thermal stress equation were solved by finite element method, and the internal heat of the material was obtained. Force field distribution. Numerical simulation results show that the thermal stress of the monolayer thin film material moves along the radial direction when the temperature is cooled. When the frequency is low, the thermal stress damage first occurs on the substrate and then the thermal stress damage occurs on the thin film. Double layer thin film material: from the laser parameter analysis, the temperature rise of the film system decreases with the increase of pulse width under the condition of the same duty cycle of the incident laser, and the thermal damage of the whole film system is analyzed from the point of view of the thermal damage of the whole film system. In time order, the SiO2 film layer first occurs the phenomenon of toroidal tensile damage, then the K9 substrate occurs the damage of circumferential tensile force, then the K9 substrate occurs thermal melting phenomenon, and finally the SiO2 film layer occurs the phenomenon of thermal melting. The results in this paper can be used to systematically analyze and reveal the interaction mechanism between laser and optical thin film, and can also provide some theoretical reference and basis for the design of optical thin film and the anti-laser strengthening technology of optical thin film.
【学位授予单位】：长春理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN249;TB383.2

【参考文献】