Geek creates DIY pulse laser pistol that can burn plastic and melt foamThe gun is called the DIY Pulse Laser Gun and was built by Patrick Priebe. The builder says that the gun has a small pulse laser head with a kW-pulse of infrared coherent light. A single shot can punch through a razor blade, plastic, and 5mm thick Styrofoam when focused.
The range of the gun is 3M for dark surfaces and the shot will make a stinging flame and leave a 5mm stain behind. I bet it would burn your skin pretty well too. I donít even want to think about what it would do to your eye. The gun is about 320mm long and weighs two pounds.
It's not enough to burn a man down where he stands or even to hole him, but it is a start.