抄録
A high power YAG laser processing system, in which the beams of three YAG lascrs (two 2.0kW continuous wave oscillator and a 1.5kW pulsed oscillator) were integrated into a single optical fiber, was developed. The beams of three lasers were focused at the input end of the optical fiber and transmitted to the processing point through the optical fiber. It was confirmed that the energy density distribution of the integrated beam even at the defocused point of the processing optics was similar to that of one oscillator without splitting to the three beams, and complex pulse shape control of the laser power became possible by integrating modulated beams of three lasers. Using this processing system, it was also confirmed that the penetration depth depended on a superimposing delay time of a pulsed laser beam to continuous wave laser modulated beams in a rectangular shape. Effective delay time of the pulsed laser beam was two or three milliseconds for the production of the deepest penetration in welding of SUS304 stainless steel.
