Femtosecond technology for precision manufacturing: fundamental and technical aspects

During the past few years research groups demonstrated the potential of femtosecond pulses for ultra-precise machining. Soon industry became interested in the new technique which promises to get rid of precision deficits occurring when using longer pulses. As possible applications drilling of nozzles, structuring of tribological surfaces and sharpening of diamond tools are considered among others. Initial investigations of such industrial applications soon showed, however, several unexpected quality problems such as formation of recast, ripples and irregular hole shapes even in the femtosecond pulse regime. After describing the problems this contribution will present some progress in fundamental understanding of the ultrafast ablation process. On the basis of this knowledge technical means have been developed allowing to achieve an unprecedented level of accuracy at acceptable expenses. The latter being strongly influenced by the shortness of the laser pulse, a comparison between pico- and femto-second regime will be presented.