Abstract Femtosecond laser-induced surface structures have been extensively investigated over decades, however, their formation is not well controlled especially for the practical use in the photonic field. We here report the highly regular nanostructure formation within the grooves of the Fe-based metallic glass, upon irradiation of two temporally delayed femtosecond laser beams. For the case of micrometer-sized groove, multiple chains of spindle-like nanostructures are developed, with the spatial periods of 667 nm and 180 nm for the chain and spindle distributions, respectively. Their arrangement properties can be modulated by varying laser parameters. On the other hand, for the case of submicrometer-sized groove, there is only one chain of spindle-like nanostructures formed inside with the improved regular appearance. Two physical effects, including the plasmonic field generation from the groove edges and the surface magnon polariton excitation within the groove, are considered responsible for the phenomena, which consequently result in the spatial interlocking of two types of ripples. The theoretical analyses match well the experimental observations.

中文翻译：

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激光诱导铁基金属玻璃微槽内规则的纳米结构链

摘要 飞秒激光诱导的表面结构已经被广泛研究了几十年，然而，它们的形成并没有得到很好的控制，尤其是在光子领域的实际应用中。我们在这里报告了在照射两个时间延迟的飞秒激光束后，在 Fe 基金属玻璃的凹槽内形成高度规则的纳米结构。对于微米尺寸的凹槽，形成了多条纺锤状纳米结构链，链和纺锤分布的空间周期分别为 667 nm 和 180 nm。它们的排列特性可以通过改变激光参数来调制。另一方面，对于亚微米尺寸的凹槽，内部仅形成一条纺锤状纳米结构链，具有改进的规则外观。两种物理效果，包括从凹槽边缘产生的等离子体场和凹槽内的表面磁振子极化子激发，被认为是造成这种现象的原因，从而导致两种类型的波纹的空间互锁。理论分析与实验观察非常吻合。