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。

Printing stable color with a lithography-free and environment-friendly technique is in high demand for applications. We report a facile strategy of ultrafast laser direct writing (ULDW) to produce large-scale embedded structural colors inside transparent solids. The diffraction effect of gratings enables effective generation of structural colors across the entire visible spectrum. The structural colors inside the fused silica glass have been demonstrated to exhibit excellent thermal stability under high temperature up to 1200°C, which promises that the written information can be stable for long time even with unlimited lifetime at room temperature. The structural colors in the applications of coloring, anti-counterfeiting, and information storage are also demonstrated. Our studies indicate that the presented ULDW allows for fabricating large-scale and high thermal-stability structural colors with prospects of three-dimensional patterning, which will find various applications, especially under harsh conditions such as high temperature.

为了改善高能流密度飞秒激光的烧蚀质量，使用法布里珀罗腔产生子脉冲间隔在1~3 500 ps内连续可调的飞秒激光脉冲序列，系统探究了单个飞秒高斯脉冲与不同脉冲间隔的脉冲序列在硅上烧蚀的孔型质量。实验结果显示，子脉冲间隔在50~100 ps范围内时，孔边缘的冠状重熔物大大减少，其厚度仅为单个飞秒高斯脉冲的40%，周围基底几乎没有粘连的粉尘或热损伤痕迹，孔型品质因子数值从单个飞秒脉冲的0.52提升至0.89。本文报道的飞秒激光脉冲序列，基于后续子脉冲与喷出物的二次烧蚀原理，子脉冲间隔在50~100 ps范围内时，后续子脉冲能够最大程度的雾化喷出物，从而减少冠状重熔物与高温粉尘污染损伤，烧蚀质量得到改善。

利用飞秒激光双光束干涉技术，结合柱透镜线扫描技术，在30 s内制备了面积为10 mm×10 mm的微米-纳米复合结构，极大地提升了激光加工效率。飞秒激光刻蚀后的硅表面包含双光束干涉引起的长周期微米结构，以及飞秒激光诱导的纳米周期结构。微米-纳米复合结构极大地提升了表面粗糙度，在毛细效应的作用下，硅在空气中显示出超亲水性，接触角从40°降为0°。测量烧蚀前后硅表面的X射线光电子能谱，发现激光加工后硅表面的Si-OH和H₂O分子的含量分别增加22.3%和13.6%，这进一步增强了硅表面的亲水性。随着激光照射功率的增加以及扫描速度的下降，硅表面接触角逐步下降。本文研究为高效制备大面积超亲水结构提供了新方法，在热传导、生物芯片等领域具有潜在的应用价值。

基于空间光调制器的飞秒激光时空干涉方法，改变800 nm飞秒激光能流密度和累积脉冲数，在316镜面不锈钢上高效率、高质量地制备了面积为5 mm×5 mm的双尺度的类鲨鱼皮肤微纳米仿生结构，并研究了该结构在不同激光照射条件下的润湿性。在激光能流密度为1.37 J/cm²，累积脉冲数为30~40的条件下，不锈钢表面碳元素含量最多增加了13.22%，润湿性由亲水（接触角88°）转变为超疏水，接触角高达165°。本研究利用灵活、高效的飞秒激光时空干涉加工方法，得到了稳定的超疏水表面，为仿生结构制备提供了新思路。

Inhomogeneity and low efficiency are two important factors that hinder the wide application of laser-induced periodic surface structures. Two-beam interference is commonly used to fabricate gratings with interference periods. This study reports regular and uniform periodic ripples fabricated efficiently by the interference of two femtosecond laser beams via a cylindrical lens. The interference period is adjusted to be an integer multiple of the wavelength of a surface plasmon polariton. Regular and uniform subwavelength nanogratings (RUSNGs) on a silicon wafer of a diameter of 100 mm are fabricated with a scanning velocity of 6–9 mm/s. Bright and pure colors (including purple, blue, and red) are demonstrated on different patterns covered with RUSNGs.

This Letter reports the formation of periodic surface structures on Ni–Fe film irradiated by a single femtosecond laser pulse. A concave lens with a focus length of 150 mm is placed in front of an objective (100×, NA=0.9), which transforms the Gaussian laser field into a ring distribution by the Fresnel diffraction. Periodic ripples form on the ablation area after the irradiation of a single femtosecond laser pulse, which depends on the laser polarization and laser fluence. We propose that the ring structure of the laser field leads to a similar transient distribution of the permittivity on the sample surface, which further launches the surface plasmon polaritons. The interaction of the incident laser with surface plasmon polaritons dominates the formation of periodic surface structures.