By "working," let's be clear: This laser is not powerful enough to sever a necromorph's limbs—not unless it is heavily sedated, if not already not-undead. It'll still burn wood and, well, I wouldn't stare directly at it.
More than just five lasers in a swell housing, this plasma cutter, built by Patrick Priebe of Laser-Gadgets, also has a rotating assembly and two battery ejects that function like clip ejections/reloading. See for yourself in the video.
No, he is not providing plans for building one yourself. That seems like a responsible thing to do, given the mayhem something like this could cause in mass production. Its known specs: two 30-milliwatt green lasers used only to aim, and two 1,500 milliwatt blue lasers to do the burning. It uses four lithium-ion batteries.