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MANUFACTURING with short pulse lasers
MICROMACHINING WITH ULTRA-SHORT LASER PULSES IN BURST-MODE
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Daniel J. FÖRSTER 1, John LOPEZ 2, Heinz P. HUBER 1, Inka MANEK-HÖNNINGER 2
1
Laser Center HM, Munich University of Applied Sciences HM, 80335 Munich, Germany
2
Université de Bordeaux-CNRS-CEA, CELIA UMR 5107, 33405 Talence, France * inka. manek-honninger @ u-bordeaux. fr
Modern ultrafast laser systems often allow for socalled burst-mode operation. This means that trains of ultrashort pulses are emitted with intra-burst repetition rates in the MHz- or GHz-range. These operation modes offer new possibilities in micromachining of different materials such as milling, drilling, or cutting. In this article, we give a short overview of recent developments and cite some achievements in micromachining applications of different materials in these new burst-regimes.
https:// doi. org / 10.1051 / photon / 202613742
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.
Ultrafast laser processing has become a key technology for high-precision manufacturing in industries such as the automotive, the electronics and the watch industries, the medical technology, and the jewellery. Pulses with durations ranging from femtoseconds to picoseconds are used to process virtually any material with minimal burrs, negligible heat-affected zones, and excellent edge quality. This results in robust and reproducible processes for tasks such as micro drilling of injector nozzles or through holes in glass, stent cutting, trimming of electronic components, laser turning, and functional surface structuring. The high flexibility of beam guidance and scanning systems allows for easy integration into automated production lines and multi-axis platforms. As average power increases towards several 100 W and beam shaping options continue to improve, ultra-fast laser processing is increasingly being used to replace or supplement conventional mechanical and chemical processes in series production. In addition to spatial beam shaping, temporal beam shaping with pulse trains or“ bursts” containing several pulses is also possible, paving the way for increased performance.
BURST REGIMES Due to the increase in average power, strongly focused ultrashort pulse lasers often deliver much more pulse energy than is required for efficient single-pulse ablation of metals. In order to be able to use the high pulse energies more flexibly, they are redistributed
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