Materials World Network: Formation of Nanostructures at Materials Surfaces Exposed to Femtosecond Laser Pulses: Experiment and Theory

该材料世界网络(MWN)奖支持美俄合作研究飞秒激光脉冲照射下材料表面纳米结构的形成。主要目标是提供对材料反应基本机制的原子尺度的理解，这些基本机制可用于进一步推进技术应用。南佛罗里达大学的美国团队将开发理论，并对飞秒激光脉冲的初始吸收阶段进行建模，然后是材料的等时压缩、压缩波和稀疏波的传播、过热晶体的快速非平衡熔化，以及熔体的缓慢再结晶。理论/模型还将侧重于拉伸热熔体中气泡成核的基本机制和动力学，以及靶材的空化、烧蚀和剥落。莫斯科和切尔诺戈洛夫卡的俄罗斯科学院的团队将对飞秒激光脉冲的响应以及几种典型材料表面纳米结构的形成进行实验研究，并将计算得到的表面纳米结构的光学特性。通过开发激光诱导表面形貌修饰的预测性和实验验证的多物理模型，将获得更广泛的影响。互访将为学生提供一个独特的机会，让他们在一国之外获得专业经验。

This Materials World Network (MWN) award supports US-Russian collaborative research to study the formation of nanostructures at surfaces of materials irradiated by a femtosecond laser pulse. The major goal is to provide an atomic-scale understanding of fundamental mechanisms of materials response that can be used to further advance technological applications. The US team at the University of South Florida will develop theory, and perform modeling of the initial stage of absorption of a femtosecond laser pulse, followed by the isochorical compression of the material, propagation of the compression and rarefaction waves, fast non-equilibrium melting of overheated crystal, and slow resolidification of the melt. The theory/modeling will also focus on the fundamental mechanisms and kinetics of bubble nucleation in stretched hot melt, as well as cavitation, ablation, and spallation of the target material. The team at the Russian Academy of Sciences in Moscow and Chernogolovka will perform experimental investigations of response to a femtosecond laser pulse, and formation of nanostructures at the surfaces of several representative classes of materials, and will calculate the optical characteristics of resultant surface nanostructures. A broader impact will be achieved by developing predictive and experimentally validated multi-physics model of laser-induced modification of surface morphology. Reciprocal exchange visits will provide students with a unique opportunity to gain professional experience beyond one nation's borders.