基于多脉冲电子激发调控的飞秒激光诱导表面结构的机制和大面积均匀制备的研究

Ultra-fast laser fabrication has attracted lots of attention in the frontier research of manufacturing technology due to its ultra-fast, ultra-strong and high precision properties. It directly demonstrates surface modifications by micro/nano-structures by changing the natural performances through ultra-short laser-matter interaction, which plays more and more important significance in the fields of aviation, energy, biology and medical treatment. In this project, laser induced periodic structures will be explored by electron modulation through multiple pulses‘ excitation to deep understanding the important role of each pulse, the thermal and non-thermal effects and thus improving the fabrication of periodic structures uniformly in large-area. The normal rules of laser induced nano-structures will also be summarized into a model and compared with the experiments. Based on the model and modulation method, large-area of 10cm×10cm with period from 50 nm to 200 nm will be realized as well as the explores of their potential applications in optical polarization devices and optical storage.

随着人们对激光微纳加工机制和应用的研究，如何调控和大面积制备高精度的超衍射亚波长纳米结构，成为了当前研究的主要难点。飞秒激光诱导微纳结构作为一种无材料选择性、超衍射高精度的加工技术，在表面改性、微纳光子学等方面有着潜在的广泛应用，但在物理机制、纳米结构调控、高效制备方面还存在着严重的不足。本项目针对以上问题，提出了基于多脉冲技术的电子浓度空间调控技术，通过利用连续脉冲作用的脉冲强度调控及子脉冲序列的时间调控，研究诱导结构成型及演变过程中每个脉冲的作用机制，并根据结构的演变规律，提出激光诱导微纳结构的物理模型和调控技术；基于以上的调控研究，制备周期从50 nm到200nm可调、10cm×10cm的 结构表面，并探索其在光学偏振器件、光学存储方面的应用。

项目围绕激光诱导微纳结构的主要成型机制展开，通过调控脉冲序列的强度分布等，研究了超衍射加工中折射率、光场增强等光与物质的相互作用机制、周期形成机制，建立了远场控制近场的超衍射加工物理模型（O-FIB机制），实现了精度 < 20 nm、间隔/周期 < 50 nm的自由直写，利用亚阈值打印技术实现了任意面积的高精度的结构制备，支撑并探索了利用飞秒激光诱导纳米光栅、可在1000度存储超10小时、容量是现有技术的3-4个数量级的多维光存储技术。资助发表16篇期刊论文（Light: Science & Applications 1篇、Optics Letters 4篇、Laser & Photonics Review 1篇；Advanced Functional Materials 2篇），申请专利1项，授权专利1项，准备中的工作2篇，作为研究基础支撑项目负责人2021年获批面上项目一项。以上工作将从实验上打通了通向百TB每盘、写入速度MB/s的五维光存储应用技术瓶颈，将有望替代光盘、磁带/盘等大功耗环境敏感的短期存储技术。