[Dan Evans]

metal should take NO WHERE NEAR 10 exp 16 watts to burn.

Depends on the pulse width and the beam width. If the pulse is a microsecond and the beam disperses enough and if they expect the target to be a polished surface over ceramic then it might require that.

[ableChair]

I understand your point, but my recollection was that the energy levels delivered were also astronomical. Something on the order of 10 exp 21 Joules. That can't be required just to burn metal; it must be either for penetrating a media or for the radius of the beam (as one poster pointed out).