Dynamic behavior of the laser beam cutting and welding process due to instabilities of industrial high-power CO2 lasers

摘要

The temporal beam power fluctuations of a high-power CO$-2$/ laser are analyzed according to their frequency spectrum and its time dependent variation. Simultaneously to the laser beam diagnostic, signals obtained from the light emission during the cutting and welding process have been detected. By comparison of corresponding spectra the interaction between beam oscillations and process dynamics is studied. The influence on the surface structure of the processed material is discussed especially in the case of laser beam cutting. For this the spatial surface morphology is also analyzed by means of local fast Fourier transformation. The overall result is that the spectra are not constant, but show time-dependent behavior. Thus a more detailed correlation analysis is necessary for full description of dynamical beam - process-interactions.