时间整形飞秒激光诱导熔融硅表面纳米周期条纹的电子动力学研究

研究了时间整形飞秒激光在熔融硅表面诱导纳米周期条纹结构的电子动力学过程.通过引入非线性电离机制和表面等离子激元的瞬态作用机理,建立了关于时间整形飞秒激光诱导和调控熔融硅表面纳米周期条纹结构的电子动力学模型,并应用该模型研究获得了纳米条纹周期与时间整形脉冲时间间隔的定量关系.理论研究结果表明,通过调节时间整形脉冲的时间间隔可以实现操控表面等离子激元与激光瞬态干涉过程中的波矢配对,最终可实现对诱导的纳米条纹周期的调控.此模型预测得到的纳米条纹周期与实验结果符合得很好.该研究对于深刻理解整形脉冲链诱导材料表面纳米周期结构的电子动力学操纵机制以及对条纹周期的调控都具有重要的理论价值.

Investigation on the electron dynamics of periodic nano ripple formation on fused silica induced by temporally shaped femtosecond laser

We investigate the electron dynamic process of periodic nano ripples formation on fused silica induced by temporally shaped femtosecond laser. The dynamic model for predictions of ripple period is proposed by introducing the mechanisms of non-linear ionization and surface plasmon polaritons (SPPs) interaction. The quantitative relation between nano ripple period and temporally shaped pulse separation is obtained by using the proposed model. It is revealed that the nano ripple period can be manipulated by adjusting the temporal intervals of the temporally shaped pulses due to the transient adjustment of the wavevector matching process during ripple formation via temporally shaped pulses. The theoretical predictions of the ripple period match well with the experimental data. This study provides the fundamental understanding of transient formation mechanism of ripples, and the precise manipulating of ripple period.