The Nintendo Light Gun makes a perfect burning laser. Of course itís been gutted to make this happen. Nonetheless, the retro look canít be beat, and the gun form factor is just what you need in a laser weapon.
This will literally burn your eye out of your head, so [Justin] and his buddies over a North Street Labs are all wearing protective goggles designed for this laserís wavelength. But they also built a safety into the zapper itself. At the beginning of the video clip (embedded after the break) you will see thereís a key lock mounted in the butt. This lock completes the circuit between the battery and driver board. The 2W output is achieved by a 445nm M140 diode. A lot went into the heat sink and mounting cylinder to make sure the diode doesnít just burn up after a few seconds of use.

http://hackaday.com/2012/09/21/nes-l...laser-upgrade/