Center for Physical Sciences and Technology, Savanoriu Ave. 231, Vilnius LT-02300, Lithuania.
Istituto di Fotonica e Nanotecnologie - CNR, P.za Leonardo da Vinci 32, I-20133 Milano, Italy.
Sci Rep. 2017 Jan 9;7:39989. doi: 10.1038/srep39989.
Understanding of material behaviour at nanoscale under intense laser excitation is becoming critical for future application of nanotechnologies. Nanograting formation by linearly polarised ultra-short laser pulses has been studied systematically in fused silica for various pulse energies at 3D laser printing/writing conditions, typically used for the industrial fabrication of optical elements. The period of the nanogratings revealed a dependence on the orientation of the scanning direction. A tilt of the nanograting wave vector at a fixed laser polarisation was also observed. The mechanism responsible for this peculiar dependency of several features of the nanogratings on the writing direction is qualitatively explained by considering the heat transport flux in the presence of a linearly polarised electric field, rather than by temporal and spatial chirp of the laser beam. The confirmed vectorial nature of the light-matter interaction opens new control of material processing with nanoscale precision.
在强激光激发下对纳米级材料行为的理解对于纳米技术的未来应用变得至关重要。在 3D 激光打印/写入条件下，针对各种脉冲能量，在熔融石英中对线性偏振超短激光脉冲形成的纳米光栅进行了系统研究，该条件通常用于光学元件的工业制造。纳米光栅的周期显示出对扫描方向的取向的依赖性。在固定激光偏振的情况下，纳米光栅波矢也发生了倾斜。通过考虑存在线性偏振电场时的热输运通量，而不是通过激光束的时间和空间啁啾，定性地解释了导致纳米光栅的几个特征对写入方向的这种特殊依赖性的机制。光物质相互作用的已证实的矢量性质为具有纳米级精度的材料加工提供了新的控制手段。
