Product Code: ICA10_M102

Critical Performance Aspects of Ultrashort Pulse Laser Materials Processing at High Repetition Rates and Average Powers (Invited Presentation)
Authors:
Antonio Ancona, CNR-IFN; Bari Italy
Sven Döring, Friedrich-Schiller-University Jena; Jena Germany
Steffen Hädrich, Friedrich-Schiller-University Jena; Jena Germany
Jens Limpert, Friedrich-Schiller-University Jena; Jena Germany
Stefan Nolte, Friedrich-Schiller-University Jena; Jena Germany
Andreas Tünnermann, Fraunhofer Institute for Applied Optics and Precision Engineering IOF; Jena Germany
Presented at ICALEO 2010

An experimental investigation is presented on the ultrashort pulse laser drilling of different metals with diverse thermal properties in the high repetition rate and high average power regime. An Ytterbium-doped fiber CPA system was used, providing pulse energies and repetition rates up to 70 μJ and 1 MHz, respectively. It has been found that at a few hundred kilohertz particle shielding causes a decrease of the ablation rate, depending on the pulse energy. At higher repetition rates, the heat accumulation effect overbalances particle shielding, but significant melt ejection affects the hole quality. The influence, in this regime, of pulse duration (800 fs to 19 ps) and wavelength (1030 nm and 515 nm) on the drilling efficiency and on the achievable precision have been further experimentally studied.