the other issue is that a laser beam is highly focused... from a laser pointer, typically <1 mm sq at 10 - 12".

from what I've noticed, using a 0.1 W 405 nm blu-ray, is that it burns a very tiny hole

through paper, pin-sized. you could superheat a similar sized piece of metal, but the surrounding metal would be rapidly cooled.

I know it seems like a cool idea, but energy would be better spent on an electrical resistance-type device.