飞秒激光辐照下金属薄膜材料的热力响应  

Thermomechanical effect of metal film heated by femtosecond pulse lasers

作　　者：李泽民[1] 郭春风[1] 齐文宗[1] 

机构地区：[1]四川大学电子信息学院,成都610064

出　　处：《激光杂志》2010年第1期30-31,共2页Laser Journal

摘　　要：考虑到金属材料热导率、弛豫时间、电子-晶格耦合系数等热力学参数随温度非线性变化因素的影响,运用具有人工粘性和自适应步长的有限差分算法,数值求解了飞秒激光辐照金属薄膜的超快热弹性模型,分析了飞秒激光辐照200nm铜膜时温度场和应力场的变化规律。结果表明:电子热导率和电子-晶格耦合系数对温度场变化有较大影响;在超快加热早期,热电子崩力在金属薄膜表面附近迅速达到峰值,后期急剧减小的热电子崩力和逐渐增大的晶格温度梯度共同决定了薄膜体系中应力场的变化。Considering of the temperature effects on the thermal conductivity,relaxation time and electron-lattice coupling coefficient,the ultrafast thermoelasticity model for metal films heated by femtosecond pulse lasers has been solved by the finite-difference method with viscosities and adaptive time steps. The variation law of temperature field and stress fields are analyzed in 200nm copper film.The numerical results indicate that the electron thermal conductivity and electron-lattice coupling coefficient have a great impact on the change of temperature field.The hot electron blast force near the irradiated surface quickly reach the maximum in the early period,then the hot-electron blast force falling rapidly and lattice temperature gradually increasing lead to the change of stress field.

关 键 词：激光技术 飞秒脉冲激光:金属薄膜 超快热弹性模型 热应力 

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