Jiang Lan, Shi Xuesong, Li Xin, Yuan Yanping, Wang Cong, Lu Yongfeng
NanoManufacturing Fundamental Research Joint Laboratory of National Science Foundation of China, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, People’s Republic of China.
Opt Express. 2012 Sep 10;20(19):21505-11. doi: 10.1364/OE.20.021505.
This study reveals that the periods, ablation areas and orientations of periodic surface structures (ripples) in fused silica can be adjusted by using designed femtosecond (fs) laser pulse trains to control transient localized electron dynamics and corresponding material properties. By increasing the pulse delays from 0 to 100 fs, the ripple periods are changed from ~550 nm to ~255 nm and the orientation is rotated by 90°. The nearwavelength/subwavelength ripple periods are close to the fundamental/second-harmonic wavelengths in fused silica respectively. The subsequent subpulse of the train significantly impacts free electron distributions generated by the previous subpulse(s), which might influence the formation mechanism of ripples and the surface morphology.
本研究表明，通过使用设计的飞秒（fs）激光脉冲序列来控制瞬态局部电子动力学和相应的材料特性，可以调节熔融石英中周期性表面结构（波纹）的周期、烧蚀区域和取向。通过将脉冲延迟从0增加到100 fs，波纹周期从550 nm变为255 nm，且取向旋转了90°。近波长/亚波长波纹周期分别接近熔融石英中的基波/二次谐波波长。脉冲序列中的后续子脉冲会显著影响先前子脉冲产生的自由电子分布，这可能会影响波纹的形成机制和表面形态。
