Thermo-elasto-plastic simulations of femtosecond laser-induced structural modifications: application to cavity formation in fused silica

Romain Beuton; Benoît Chimier; Jérôme Breil; David Hébert; Pierre-Henri Maire; Guillaume Duchateau

doi:10.1063/1.4993707

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arXiv · 1709.09632

Thermo-elasto-plastic simulations of femtosecond laser-induced structural modifications: application to cavity formation in fused silica

Romain Beuton·Benoît Chimier·Jérôme Breil·David Hébert·Pierre-Henri Maire·Guillaume Duchateau

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Abstract

The absorbed laser energy of a femtosecond laser pulse in a transparent material induces a warm dense matter region which relaxation may lead to structural modifications in the surrounding cold matter. The modeling of the thermo-elasto-plastic material response is addressed to predict such modifications. It has been developed in a 2D plane geometry and implemented in a hydrodynamic lagrangian code. The particular case of a tightly focused laser beam in the bulk of fused silica is considered as a first application of the proposed general model. It is shown that the warm dense matter relaxation, influenced by the elasto-plastic behavior of the surrounding cold matter, generates both a strong shock and rarefaction waves. Permanent deformations appear in the surrounding solid matter if the induced stress becomes larger than the yield strength. This interaction results in the formation of a sub-micrometric cavity surrounded by an overdense area. This approach also allows one to predict regions where cracks may form. The present modeling can be used to design nano-structures induced by short laser pulses.

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Romain Beuton, Benoît Chimier, Jérôme Breil, David Hébert, Pierre-Henri Maire, Guillaume Duchateau. 2017-09-27. Thermo-elasto-plastic simulations of femtosecond laser-induced structural modifications: application to cavity formation in fused silica. https://doi.org/10.1063/1.4993707

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