It looks like they raise the cutter head upwards to make the welding passes, probably spreading the beam out a bit. Do they also run it at lower power, or slower? We demand details! Anyway ...

Last time we talked about a video that purported to do plastic welding, we mentioned that the ... metal reinforcement from things like wires and staples, and donor plastic from a zip tie.

Instead of relying on fasteners to keep structures together in space, astronauts may need to use lasers to weld on the lunar surface.