This thread inspired me, and I remembered I had a duff DVD-rw drive in the loft I had kept for exactly that purpose. So over the weekend I pulled it apart and scavenged the diode. With a little work, and the optics from a cheap (and non-functional) laser pointer, I produced the MEGApointer MK1



It's not quite finished yet, I still need to recess the screws and polish it! It's got a little PSU module inside that's designed for running CPU core voltages, set to 3.5V, and runs from 3 AAA cells in a holder I scavenged from an old LED head-torch. About 32mm in diameter and perhaps 100mm long. The laser optics are adjustable. Set to produce a parallel beam it gives a spot size of about 3mm, which still has enough energy to shrink heatshrink tubing! Focussed to a minimum spot size at perhaps a foot, the beam is only around 0.2mm across, and melts plastic so fast you can write your name with it. Wave it around on the antistatic mat it's on in the picture and it leaves a trail of smoke behind The beam diverges quickly after the focus point, and at 15 feet its about 3 inches across. I'd estimate the output power is at least 150mW. It's probably capable of more.

Quite fun for a quick and dirty afternoons work.

pca