Ultra-short pulses at high average power in the Laser MicroJet

he commercially available Synova Laser MicroJet® technology combines conventional laser capabilities with compressed water jet that precisely guide laser beam in a similar manner to optical fibers. Due to physical water breakdown, technology is typically focused on the nanosecond pulse duration range. A stable beam shaping setup with a diffusor and commercial fiber to couple into water jet, was developed allowing to test Laser MicroJet® at 100-300 ps pulse duration. The change to energy intensity profile with diffuser allowed to triple coupled energy without inducing the physical breakdown in water and could be further increased by implementing 2 and 3 pulse bursts into the setup. High quality scribing was achieved at Si wafer at high scanning speed. Preliminary results on multilayer Si-wafer have demonstrated that scribing quality is in this case more feedrate dependent, limited chipping occurring at speed of commercial interest. Cutting tests were performed on semiconductors as well as on metals. On both, it was possible to achieve high quality cuts with high feedrate up to 12 mm/s with Ra < 0,3 μm.