超短脉冲激光烧蚀金属薄膜材料的热效应分析  

Thermal Effect Analysis of Metal Film Ablation by Ultra-Short Laser Pulses

作　　者：王德飞[1] 于继平[1] 郭春凤[1] 齐文宗[1] 

机构地区：[1]四川大学电子信息学院,四川成都610064

出　　处：《中国激光》2008年第10期1579-1584,共6页Chinese Journal of Lasers

摘　　要：基于双曲双温两步热传导模型,利用具有人工粘性和自适应步长的有限差分算法,对超短脉冲激光辐照金膜时的温度场进行了一维数值模拟计算。讨论了不同能量密度和脉冲宽度条件下金膜表面温度场的分布情况;分析了电子-晶格耦合系数对薄膜体内温度场的变化规律及电子-晶格耦合至热平衡所需时间的影响。结果表明.激光脉冲的能量密度和脉冲宽度对电子温度的峰值有重大影响;电子-晶格的耦合系数决定了二者的温升速率和耦合时间;电子温度及电子温度的梯度在接近表面区域迅速达到最大值,与之相应的热电子崩力是造成金属薄膜早期力学损伤的主要原因。Based on the dual-hyperbolic two-temperature and double-step heat conduction model , numerical simulation for the electron and lattice temperatures field of gold film is performed by ultra-short laser pulses, using the finite-difference method with viscositics and adaptive time steps. The temperature distributions of the electron and lattice at the front surface with different laser intensities and pulse widths were discussed. Simuhaneously, it is also analyzed that the effect of the electron lattice coupling coefficient on the change of electron lattice temperature and the time of electron-lattice coupling to thermal equilibrium. Numerical results show that the laser intensity and pulse width impact significantly on the peak of the electron temperature, and electron lattice temperature rising rate and coupling time are determined by the coupling factor. Eectron temperature and its gradient quickly reach the maximum in a small region near the irradiated surface, corresponding with high hot-electron blast force, which could be a dominating mechanism for mechanical damage at the early stage of uhra-short laser ablation.

关 键 词：激光技术 超短脉冲激光 金属薄膜 热效应分析 双曲双温模型 

分 类 号：TN249[电子电信—物理电子学] O437[机械工程—光学工程]