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SPATIAL SHAPING OF ULTRAFAST LASER BEAMS FOR ADVANCED MATERIAL PROCESSING
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Cyril MAUCLAIR * Univ Angers, LPHIA, SFR MATRIX, F-49000 Angers, France * cyril. mauclair @ univ-angers. fr
Ultrafast lasers enable material processing with remarkable precision, but exploiting the increasing power of modern laser sources remains challenging. Dynamic wavefront shaping offers a powerful solution by tailoring the focal intensity distribution in space. This article introduces the main concepts and technologies behind spatial beam shaping and illustrates how shaped beams, parallel processing and structured light can improve the flexibility and efficiency of laser processing. https:// doi. org / 10.1051 / photon / 202614044
This is an Open Access article distributed under the terms of the Creative Commons Attribution License( https:// creativecommons. org / licenses / by / 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
WHY SHAPE ULTRAFAST LASER BEAM? Ultrafast lasers have become essential tools for high-precision material processing. Their extremely short pulse duration allows energy to be deposited into matter on a timescale shorter than most thermal diffusion processes, enabling micrometric and even sub-micrometric structuring with limited heat-affected zones. Applications now range from surface functionalization and micromachining to cutting, drilling and three-dimensional modification of transparent materials.
Over the last two decades, ultrafast laser technology has undergone a major evolution. The development of robust Ytterbium-based sources and scalable amplifier architectures has considerably increased the available average power and repetition rate, while improving stability and reducing the cost per delivered watt compared with historical Ti: sapphire systems [ 1 ]. As a consequence, laser power itself is no longer the main limitation for many ultrafast processing applications.
Paradoxically, having more laser power does not necessarily mean faster or better processing. Many applications require only a few microjoules per pulse and operate within a relatively narrow fluence window.
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