<title>Laser processing with high-power gas lasers</title>

Two mid-IR gas lasers, the CO (5.3 micrometers ) and the HF (2.7 micrometers ) lasers afford higher absorptivities on metals, lower plasma absorption as compared to the CO₂ laser. On the other hand, the resonant cavity can be improved in order to deliver smaller spots sizes than the Nd:YAG laser. A whole array of these four high power IR lasers in the kW range are available at the ISL. Comparative studies in metal processing with these lasers have been undertaken. It has been shown that, due to higher absorptivities, the remelting is obtained with lower laser power.