Axel Giering

Characterization of pulsed Nd:YAG-laser beams as an optimization tool in laser drilling applications

The attainable precision and reproducibility in material treatment with pulsed Nd:YAG-lasers strongly depends on the characteristics of the laser beam itself Therefore it is essential for the process and tool optimization to have comprehensive information of the relevant laser beam data. Especially flash-lamp pumped lasers working in pulsed mode often have intense fluctuations in their temporal and spatial radiation characteristics, which are caused by a multitude of transient physical processes.This contribution shows a measuring method and device for an adequate characterization of pulsed laser sources and their beam delivery systems. The technique of spatial beam deflection used herein is able to measure energy density profiles of successive single pulses with repetition frequencies of up to 20 kHz (3 kHz real time). The measuring device can be used for off-line or in-process measurements. Its application for the laser qualification and especially its contribution to the development of a new pulsed drilling laser are demonstrated.The single pulse characterization will be presented as an in-process control tool for pulsed laser applications. Furthermore the correlation between laser beam profiles and hole shapes for the single pulse drilling process is discussed.The attainable precision and reproducibility in material treatment with pulsed Nd:YAG-lasers strongly depends on the characteristics of the laser beam itself Therefore it is essential for the process and tool optimization to have comprehensive information of the relevant laser beam data. Especially flash-lamp pumped lasers working in pulsed mode often have intense fluctuations in their temporal and spatial radiation characteristics, which are caused by a multitude of transient physical processes.This contribution shows a measuring method and device for an adequate characterization of pulsed laser sources and their beam delivery systems. The technique of spatial beam deflection used herein is able to measure energy density profiles of successive single pulses with repetition frequencies of up to 20 kHz (3 kHz real time). The measuring device can be used for off-line or in-process measurements. Its application for the laser qualification and especially its contribution to the development of a new pulsed dri...