为了制备高质量表面周期结构，利用法布里-珀罗腔对飞秒激光进行时域整形，输出子脉冲间隔在1~300 ps内灵活可调的飞秒激光脉冲串，在硅表面诱导亚波长周期条纹。实验结果显示，利用飞秒激光脉冲串诱导得到的亚波长周期条纹明显优于原始高斯光诱导的亚波长周期条纹。利用子脉冲间隔为100 ps的脉冲串诱导的亚波长条纹最佳，条纹周期为1 008 nm，结构取向角为2.8°，边缘粗糙度为3.9 nm，可达到光刻工艺的标准。

This paper reports the fabrication of regular large-area laser-induced periodic surface structures (LIPSSs) in indium tin oxide (ITO) films via femtosecond laser direct writing focused by a cylindrical lens. The regular LIPSSs exhibited good properties as nanowires, with a resistivity almost equal to that of the initial ITO film. By changing the laser fluence, the nanowire resistances could be tuned from 15 to 73 kΩ/mm with a consistency of ±10%. Furthermore, the average transmittance of the ITO films with regular LIPSSs in the range of 1200–2000 nm was improved from 21% to 60%. The regular LIPSS is promising for transparent electrodes of nano-optoelectronic devices—particularly in the near-infrared band.

Femtosecond laser-induced periodic surface structures (LIPSS) have several applications in surface structuring and functionalization. Three major challenges exist in the fabrication of regular and uniform LIPSS: enhancing the periodic energy deposition, reducing the residual heat, and avoiding the deposited debris. Herein, we fabricate an extremely regular low-spatial-frequency LIPSS (LSFL) on a silicon surface by a temporally shaped femtosecond laser. Based on a 4f configuration zero-dispersion pulse shaping system, a Fourier transform limit (FTL) pulse is shaped into a pulse train with varying intervals in the range of 0.25–16.2 ps using periodic π-phase step modulation. Under the irradiation of the shaped pulse with an interval of 16.2 ps, extremely regular LSFLs are efficiently fabricated on silicon. The scan velocity for fabricating regular LSFL is 2.3 times faster, while the LSFL depth is 2 times deeper, and the diffraction efficiency is 3 times higher than those of LSFL using the FTL pulse. The formation mechanisms of regular LSFL have been studied experimentally and theoretically. The results show that the temporally shaped pulse enhances the excitation of surface plasmon polaritons and the periodic energy deposition while reducing the residual thermal effects and avoiding the deposition of the ejected debris, eventually resulting in regular and deeper LSFL on the silicon surface.