The InnoSlab laser design, already established for neodymium doped laser materials, was applied to ytterbium doped laser materials. Nearly transform limited sub-picosecond pulses at 400 W average power at room temperature and without using CPA technique have been achieved so far. This compact, diode- pumped Yb:YAG InnoSlab fs-oscillator-amplifier system, scalable to the kilowatt range was applied for ablation, cutting and drilling of various materials. Processed materials are carbon and oxide based ceramics like SIGRADUR®, CSiC and fiber- reinforced aluminum oxide, pure metals and alloys like copper, aluminum, NiAl and CMSX. The samples are investigated by light microscopy and SEM, cross- sections are prepared. For the cutting and drilling experiments pulse energies of about one micro-joule and varying repetition rates between 1 and 76 MHz are used. Comparative experiments on the same materials are performed using a cw-fibre-laser. The influence of the repetition rate and the scanning velocity on the efficiency and quality of the structuring results are investigated. An estimation of the optimum process parameters repetition rate and scanning velocity for the ablation process for different materials will be given.

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