摘要
通过双温模型(TTM)结合Richardson-Dushman方程对多脉冲飞秒激光烧蚀铜箔的热电子发射以及温度场进行了数值模拟。在模拟的过程中充分考虑了随着飞秒激光脉冲个数的改变,铜箔对飞秒激光的反射率、表面吸收率和表面吸收系数的变化等因素,部分改写了飞秒激光光源项,从而实现了多脉冲飞秒激光烧蚀铜箔的热电子发射和温度场的动态数值模拟。数值模拟发现,随着脉冲个数的增加和脉冲间隔的减小,铜箔表面的反射率和表面吸收系数将明显减小,表面吸收率将明显增大,这一变化对铜箔的电子发射以及多脉冲飞秒激光照射下铜箔的温度场具有重要影响;而随着距铜箔表面深度的增加,这些影响将逐渐减小。
The characteristics of thermal electron emission of the metal films ablated by multi-pulse femtosecond laser are investigated using the two-temperature model（TTM） coupled with the Richardson-Dushman equation.In the numerical simulation,the variations of reflectivity and absorption of metal films with the change of the number of femtosecond laser pulses and pulse spacing are considered and the dynamic numerical simulation is achieved.It is found that,with the change of femtosecond laser pulse number and pulse spacing,the reflectivity and absorption coefficient of metal films would be raised and the absorptivity would be decreased.And the change of the parameters would have a significant influence on the thermal electron emission and the temperature field of metal films.Meanwhile,with the depth raising,the influence would be diminished.
出处
《激光与光电子学进展》
CSCD
北大核心
2012年第8期171-177,共7页
Laser & Optoelectronics Progress
基金
国家自然科学基金(51175348)
深港创新圈计划(ZYB200907090135A)
广东省教育厅重点实验室开放基金(201002)资助课题
