ANALYSIS OF PERIODIC NANOSTRUCTURES FORMATION ON A GOLD SURFACE UNDER EXPOSURE TO ULTRASHORT LASER PULSES NEAR THE MELTING THRESHOLD

Autor: D. S. Ivanov, V. P. Lipp, A. Blumenstein, V. P. Veiko, Y. B. Yakovlev, V. V. Roddatis, M. E. Carcia, B. Rethfeld, J. Ihlemann, P. Simon
Jazyk: English<br />Russian
Rok vydání: 2015
Předmět:
Zdroj: Naučno-tehničeskij Vestnik Informacionnyh Tehnologij, Mehaniki i Optiki, Vol 15, Iss 6, Pp 984-999 (2015)
Druh dokumentu: article
ISSN: 2226-1494
2500-0373
DOI: 10.17586/2226-1494-2015-15-6-984-999
Popis: Subject of Study. The mechanism of surface restructuring by ultrashort laser pulses involves a lot of fast, non-equilibrium, and interrelated processes while the solid is in a transient state. As a result, the analysis of the experimental data cannot cover all the mechanisms of nanostructuring. We present a direct comparison of a simulation and experimental results of surface nanomodification induced by a single laser pulse. Method. The experimental results were obtained by using a mask projection setup with a laser wavelength equal to 248 nm and a pulse length equal to 1.6 ps. This setup is used to produce an intensity grating on a gold surface with a sinusoidal shape and a period of 500 nm. The formed structures were analyzed by a scanning and transmission electron microscope, respectively. Then a hybrid atomistic-continuum model capable of capturing the essential mechanisms responsible for the nanostructuring process was used for modeling the interaction of the laser pulse with a thick gold target. Main Results. A good agreement between simulation and experimental data justifies the proposed approach as a powerful tool revealing the physics behind the nanostructuring process at a gold surface and providing a microscopic insight into the dynamics of the structuring processes of metals in general. The presented model, therefore, is an important step towards a new computational tool in predicting materials response to an ultrashort laser pulse on the atomic scale and properties of the modified surfaces. Practical Relevance. This detailed understanding of the dynamics of the process will pave the way towards pre-designed topologies for functionalized surfaces on the nano- and micro-scales.
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