Spatial shaping of femtosecond laser beam for high speed multi-scale surface structuring of materials

Abstract : The interaction of femtosecond light pulses with materials has been widely studied [1] and put forward in the field of micro and nano processing. The interaction region usually presents a reduced thermally affected zone compared to longer laser irradiations (nanosecond and beyond). The characteristics of the laser-induced structures depend on the focusing conditions, the energetic conditions and the physical properties of the material. In particular, fine tuning of the fluence and energetic dose enables the generation of an extended variety of surface self-organization on sub-micrometric scale known as ripples [2]. This micro nano structuration has been shown to modulate the physical properties of the surface with interest in tribology, wettability and color marking. This unique characteristic of ultrashort lasers in micro processing has triggered worldwide research efforts to increase the efficiency of the technique to qualify it for industrial demands. In this view, two major aspects are the fine control of the intensity distribution and the surface treatment rapidity. Concerning the first point, it has been shown that a wavefront modulation on the propagating laser permits to obtain user-defined intensity distributions on the surface to be machined [3]. Secondly, the problem of speed can be addressed by demultiplying the focal spot into several foci using the same technique [4]. In the present report, we demonstrate the possibility to generate multiple processing spots simultaneously with arbitrary shapes and fluence levels. We combine this beam shaping technique with a laser deflection system to achieve high speed surface functionalization (see figure 1a)). By using diverse fluence levels combined with proper beam trajectories, several multi scale structurations of the surface are presented. Also, the fidelity of the beam shape in the context of high peak power is experimentally investigated. In particular we underline situations where the beam undergoes substantial non linear propagation before reaching the target. Detrimental consequences on the regularity of the beam shape are observed and discussed [1] B. N. Chichkov, C. Momma, S. Nolte, F. von Alvensleben, A. Tuennermann, Femtosecond, picosecond and nanosecond laser ablation of solids, Applied Physics A, vol. 63, pp. 109-115, (1996). [2] D. Dufft, A. Rosenfeld, S. K. Das, R. Grunwald, J. Bonse, Femtosecond laser-induced periodic surface structures revisited: A comparative study on ZnO, Journal of Applied Physics A, vol. 105, pp. 034908-1-9, (2009). [3] N. Sanner, N. Huot, E. Audouard, C. Larat, J.-P. Huignard, B. Loiseaux, Programmable focal spot shaping of amplified femtosecond laser pulses, Optics Letters, vol. 30, pp. 1479-1481 (2005). [4] C. Mauclair, G. Cheng, N. Huot, E. Audouard, A. Rosenfeld, I. V. Hertel, R. Stoian, Dynamic ultrafast laser spatial tailoring for parallel micromachining of photonic devices in transparent materials, Optics Express, vol. 17, Issue 5, pp. 3531-3542, (2009).
Type de document :
Communication dans un congrès
The 6th International Congress on Laser Advanced Materials Processing LAMP2013 July 23-26, 2013 Toki Messe, Niigata, Japan, Jul 2013, niigata, Japan
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Contributeur : Cyril Mauclair <>
Soumis le : mercredi 2 juillet 2014 - 14:45:51
Dernière modification le : jeudi 11 janvier 2018 - 06:20:35

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  • HAL Id : ujm-01017416, version 1

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Cyril Mauclair, David Pietroy, Emmanuel Baubeau, Razvan Stoian, Eric Audouard. Spatial shaping of femtosecond laser beam for high speed multi-scale surface structuring of materials. The 6th International Congress on Laser Advanced Materials Processing LAMP2013 July 23-26, 2013 Toki Messe, Niigata, Japan, Jul 2013, niigata, Japan. 〈ujm-01017416〉

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