飞秒激光诱导金属钨表面周期性自组织结构的研究

Investigation of Femtosecond Laser-Induced Periodic Surface Structure on Tungsten

飞秒激光诱导金属表面周期性自组织微纳米条纹结构,在调控热辐射源、摩擦、超亲水性、超疏水性和打标等方面具有广泛的应用前景.研究了800nm飞秒激光诱导金属钨表面周期性自组织结构的形成规律和形成机理.采用Sipe干涉模型和有限时域差分法,仿真了第1个飞秒激光脉冲刻蚀后随机粗糙表面引起的激光电磁场能量表面分布和第20个脉冲后低空间频率条纹结构引起的激光电磁场能量表面分布.揭示了低空间频率条纹与高空间频率条纹的形成机理,考察了表面微观形貌的演化和条纹周期随着脉冲增多而递减的现象.

Femtosecond laser-induced periodic surface structure（LIPSS）has the potential applications in tunable thermal source,tribology,super-hydrophilicity,super-hydrophobicity,marking and so on.LIPSS formation and mechanism on tungsten with a 800 nm femtosecond laser are investigated.The electromagnetic energy distribution on random rough surface after the first laser pulse and the energy distribution of electromagnetic field induced by low-spatial-frequency LIPSS after 20 pulses are simulated by Sipe interference model and finite-difference timedomain（FDTD）method.The formation mechanism of low-spatial-frequency and high-spatial-frequency LIPSS（HSFL）is disclosed.The evolution of surface morphology and the phenomena of spatial period decreasing with the increase of laser pulse number are also investigated.