中国物理B ›› 2011, Vol. 20 ›› Issue (2): 24210-024210.doi: 10.1088/1674-1056/20/2/024210

• CLASSICAL AREAS OF PHENOMENOLOGY • 上一篇    下一篇

Thermal characteristics of double-layer thin film target ablated by femtosecond laser pulses

高勋, 宋晓伟, 林景全   

  1. School of Science, Changchun University of Science and Technology, Changchun 130022, China
  • 收稿日期:2010-08-01 修回日期:2010-09-01 出版日期:2011-02-15 发布日期:2011-02-15
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 60978014), the Natural Science Foundation of Jilin Province (Grant No. 20090523) and the Educational Commission of Jilin Province (Grant No. [2008]297).

Thermal characteristics of double-layer thin film target ablated by femtosecond laser pulses

Gao Xun(高勋)†, Song Xiao-Wei(宋晓伟), and Lin Jing-Quan(林景全)   

  1. School of Science, Changchun University of Science and Technology, Changchun 130022, China
  • Received:2010-08-01 Revised:2010-09-01 Online:2011-02-15 Published:2011-02-15
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 60978014), the Natural Science Foundation of Jilin Province (Grant No. 20090523) and the Educational Commission of Jilin Province (Grant No. [2008]297).

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摘要： Thermal characteristics of tightly-contacted copper--gold double-layer thin film target under ablation of femtosecond laser pulses are investigated by using a two-temperature theoretical model. Numerical simulation shows that electron heat flux varies significantly on the boundary of copper--gold film with different maximal electron temperature of 1.15×103 K at 5 ps after ablating laser pulse in gold and copper films, which can reach a balance around 12.6 ps and 8.2 ps for a single and double pulse ablation, respectively, and in the meantime, the lattice temperature difference crossing the gold--copper interface is only about 0.04×103 K at the same time scale. It is also found that electron--lattice heat relaxation time increases linearly with laser fluence in both single and double pulse ablation, and a sudden change of the relaxation time appears after the laser energy density exceeds the ablation threshold.

Abstract: Thermal characteristics of tightly-contacted copper–gold double-layer thin film target under ablation of femtosecond laser pulses are investigated by using a two-temperature theoretical model. Numerical simulation shows that electron heat flux varies significantly on the boundary of copper–gold film with different maximal electron temperature of 1.15×103 K at 5 ps after ablating laser pulse in gold and copper films, which can reach a balance around 12.6 ps and 8.2 ps for a single and double pulse ablation, respectively, and in the meantime, the lattice temperature difference crossing the gold–copper interface is only about 0.04×103 K at the same time scale. It is also found that electron–lattice heat relaxation time increases linearly with laser fluence in both single and double pulse ablation, and a sudden change of the relaxation time appears after the laser energy density exceeds the ablation threshold.

Key words: femtosecond laser ablation, pulse train, two-temperature model

中图分类号:  (Ultrafast processes; optical pulse generation and pulse compression)

  • 42.65.Re
44.20.+b (Boundary layer heat flow) 65.40.De (Thermal expansion; thermomechanical effects)