高反射金属表面周期结构的飞秒激光主动调控机理研究

Surface micro/nano structure is the key functional structure of aerospace and new energy micro devices/systems. Femtosecond laser micro/nano fabrication has outstanding advantages in surface micro/nano structure manufacturing. This proposed project will investigate formation mechanisms and controlled manufacturing of periodic structures on metal surface induced by femtosecond laser. This project will 1）understand and control the interaction between photon-electron from the viewpoint of ultrafast electron dynamics during femtosecond laser micro/nano fabrication; 2）develop a new model considering both the laser wave–particle duality and transient localized changes of material properties based on improved two temperature model; 3) reveal the formation mechanism of femtosecond laser induced surface periodic structures on metals; 4) explore manipulate mechanisms of femtosecond laser induced surface periodic structures by controlling laser beam shaping and interaction between photon and electron. With a theoretical model to be developed, high-quality, high-precision and large area surface periodic structure are fabricated by shaped femtosecond laser. This project will study the effect of surface structure on its anti - reflective properties. The proposed project will provide basic manufacturing techniques for aerospace and new energy key structures/devices, and the country's major needs.

表面微纳结构是航空航天、新能源等领域微型器件/系统的关键功能结构，飞秒激光微纳制造技术在表面微纳结构制造方面具有突出优势。本项目针对飞秒激光诱导金属表面周期结构难以实现主动调控且机理不明等问题，从电子层面理解和调控飞秒激光加工过程中光子-电子相互作用，综合考虑激光波粒二象性和材料瞬时局部特性，研究光场传播、能量吸收和传递，建立基于激光波粒二象性的改进双温模型，揭示飞秒激光诱导高反射金属表面周期结构的形成机理；以光束整形为手段，通过调控加工过程中光子-电子相互作用实现金属表面周期结构的主动调控，揭示高反射金属表面周期结构的飞秒激光主动调控机理及加工新方法；根据飞秒激光主动调控机理设计激光能量分布，制备高质量、高精度、大面积金属表面周期结构，研究表面周期结构对其抗反射特性的影响规律，为航空航天、新能源等器件/系统的关键功能结构的可控加工新方法奠定基础，为国家重大需求提供关键制造支撑。

表面微纳结构是航空航天、新能源等领域微型器件/系统的关键功能结构，飞秒激光微纳制造技术在表面微纳结构制造方面具有突出优势。本项目针对飞秒激光诱导金属表面周期结构难以实现主动调控且机理不明等问题，本项目通过综合考虑激光波粒二象性和材料瞬时局部特性，建立基于激光波粒二象性的改进双温模型，揭示飞秒激光诱导金属表面周期结构的形成过程和形成机理。基于模型烧蚀判定准则，研究飞秒激光烧蚀金属表面形貌，建立基于激光波粒二象性的金属加工模型，揭示飞秒激光诱导金属表面周期结构的形成机理，认为入射激光与其诱导产生的表面等离子体波之间的相互作用是金属亚波长表面周期结构形成的重要原因。另外，通过飞秒激光加工条件的改变，可对飞秒激光诱导金属亚波长表面周期结构进行调控，本研究中通过改变激光脉冲个数、脉冲能量、加工方式、激光波长等实现金属亚波长表面周期结构的有效调控。此外，表面周期结构的制备对材料表面抗反射性能的影响也进行了系统的研究，并总结规律，得到优化工艺，制备大面积一致性抗反射表面周期结构。