In high-precision laser material processing, ultrashort pulse laser sources are used in order to minimize heat affected zones. So that the material does not overheat, however, system technology is required which distributes the required highaverage power over the surface quickly. There are two possible approaches: increasing either the process parallelism, on the one hand, or its speed, on the other. Increasing the scanning speed requires low pulse energies and high repetition rates. At high repetition rates, the maximum speed of galvanometer scanners is not sufficient for the necessary pulse spacing, so that lasers have to be operated with reduced power.
The polygon mirror of a polygon scanner rotates at high and constant speed, thus increasing maximum scanning speed. This allows a low pulse overlap for optimum processing results and the utilization of full laser power. To achieve twodimensional processing, the scanning line is shifted by moving the workpiece or by utilizing an additional galvanometer mirror. The pulse and position-accurate modulation of the laser beam is synchronized to the position of the polygon and the second axis.