Application potential of laser with strong focusability Available to Purchase

Thin disk lasers as well as fibre lasers are distinguished by their good focusability and high efficiency. With the availability of the 4 kW thin disk laser, keyhole welding with focus diameters down to 75 µm became possible. This allows comparing the influence on the welding depth of the different focus diameter regimes that can be typically realized by lamp-pumped solid state and thin disk lasers. As has been proved with lamp pumped devices, the welding depth scales with the inverse focus diameter down to 300 µm at same laser power. This dependence is confirmed by the experiments to be discussed with the thin disk laser for focus diameters down to about values of 150 to 200 µm. For smaller diameters, however, some unexpected results were found that will be discussed in detail. Under these conditions the divergence angle of the laser beam plays a role on the achievable welding depth as well. Additionally, the divergence angle has considerable influence on the quality of the weld seam.