High average power lasers, hundreds of watts to kilowatts, are common in industrial environments where the beams are used to cut, weld, or engrave high melting point materials such as metals. In the research environment high peak power lasers, from gigawatts to terawatts, are common for pulsed lasers (ns, ps and fs) used in ablation and ultrafast spectroscopy. However, due to the low pulse repetition frequencies, those lasers normally have intermediate average powers in the order of a few watts. In the last few years, groups at the University of Toronto have started requiring high-average power lasers for their projects. These lasers’ powers range from a few hundred watts to one kilowatt. Normally these types of lasers are completely enclosed and certified as “class I working environment” by the laser's manufacturer, but the particular needs of some projects they are used on require open beam lasers.
In this paper, we'll focus on two lasers, one used for welding in a machine shop environment and the other in a research group developing a novel metal 3D printer. We will discuss the challenges of controlling different types of hazards, such as high-power beams, respiratory hazards connected to metal powder, Oxygen displacement by inert gases, etc. Changes in the laser safety training designed for the operators (craftspeople), who don't have much experience working with lasers and have little knowledge about physics will be also presented.