INVESTIGATION OF THERMAL LENSING TIME CONSTANTS IN LASER PROCESSING OPTICS

摘要

High-power solid-state lasers at high beam qualityexperience a rapid development these days. They are indemand for the manufacturing of e.g. lightweightcomponents and parts in the electronics industry. Asshown in many publications this brings up the problemof beam handling i.e. allowing the beam to propagateto the material interaction zone with constant beamparameters.One of the challenges that engineers encounter is thefocus shift induced especially by optical componentsused in transmission. As this effect is stronglyinfluencing material processing it is a major issue tomeasure and classify the temporal formation of theeffect until steady state condition is reached.The temporal behaviour of the thermal lensing instandard laser welding optics was measured usingdifferent setups. A comparison between a fast andapproximate method on the one hand and a moreelaborate but also more time consuming method on theother hand will be drawn.