High performance scanner for remote welding with Nd:YAG lasers

Abstract

Robot-based remote welding with solid-state lasers increasingly becomes an issue for automotive industry due to low process costs in comparison to spot welding or conventional laser welding. When discussing robot-based remote welding, very often the necessity of high beam qualities is emphasized, which can so far only be delivered by diode-pumped Yb:YAG disc and fibre lasers. However, industrially qualified and widely-used today are Nd:YAG rod lasers with distinctly lower beam qualities. Employing these beam sources for remote welding with standard galvanometer-based scanners either results in very small workspaces or very big spot sizes, in both cases lowering overall process efficiency. A new scanner concept for high-power rod lasers is introduced that provides workspaces which are at least twice as large as available scanners while maintaining a reasonable focal diameter. This way, investment in new laser sources can be reduced substantially, which makes remote welding a very attractive choice for users already employing lasers in manufacturing.