飞秒激光烧蚀硅材料表面形成周期波纹形貌研究

发布时间：2018-06-19 02:10

本文选题：Sipe-Drude模型 + 表面等离子体激元　；参考：《物理学报》2017年10期

【摘要】：基于Sipe-Drude模型和表面等离子体激元(SPP)的干涉理论分别对单脉冲飞秒激光诱导硅表面形成低频率周期性波纹进行分析研究.探究了波长800 nm、脉宽150 fs的单个飞秒激光烧蚀硅造成不同激发水平下波纹形貌的变化,考虑到材料的光学性质变化(由Drude模型得到的介电常数变化),引入包含双温方程的电子数密度模型.计算结果表明,Sipe-Drude和SPP理论都适用于分析和解释高激发态下周期性波纹,但Sipe-Drude理论更适合分析更为广泛的周期性波纹结构.同时,波纹延伸方向总是垂直于入射激光偏振方向,其空间周期略小于激光波长,并受到入射激光通量的影响.在激光通量为0.38 J/cm~2时,波纹周期达到最小值.另外,还得到了不同入射角度的波纹周期变化情况,并在不同偏振态下随入射角度增大时波纹周期呈现相反的变化趋势.该研究对于理解飞秒激光造成硅表面形成周期结构及其在加工硅材料领域具有重要参考意义.
[Abstract]:Based on the Sipe-Drude model and the surface plasmon SPP theory, the low frequency periodic ripples on silicon surface induced by single pulse femtosecond laser are studied. A single femtosecond laser ablation of silicon with a wavelength of 800 nm and a pulse width of 150 fs has been investigated. Considering the change of the optical properties of the material (the change of dielectric constant obtained from the Drude model), an electron number density model containing the two-temperature equation is introduced. The results show that both Sipe-Drude and SPP theories are suitable for the analysis and interpretation of periodic ripples in high excited states, but the Sipe-Drude theory is more suitable for the analysis of more extensive periodic ripple structures. At the same time, the ripple extension direction is always perpendicular to the polarization direction of the incident laser, and its spatial period is slightly smaller than the wavelength of the laser, which is influenced by the incident laser flux. When the laser flux is 0.38 J / cm ~ 2, the ripple period reaches the minimum. In addition, the variation of ripple period with different incidence angles is obtained, and the variation trend of ripple period is opposite with the increase of incidence angle in different polarization states. This study has important reference significance for understanding the periodic structure of silicon surface caused by femtosecond laser and its application in the field of processing silicon materials.
【作者单位】：电子工程学院脉冲功率激光技术国家重点实验室;
【基金】：脉冲功率激光技术国家重点实验室基金(批准号:SKL2014ZR03)资助的课题~~
【分类号】：TN249

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