Multispectrum laser....wow, what’s the power need for that? The whole physical basis of lasers is that they are composed of coherent light.

Actually, basic optics shows that the only place the beam is narrow is at its focus....it’s much wider and impacted by the atmosphere for the majority of its travel length.

Both situations require the same energy to evaporate the same amount of water. The big challenge is whether the laser with it’s focused beam will need to encounter the whole kilo of water, or can it “bypass” most of it and avoid losing power due to absoption and diffraction....without precise focusing, the laser will…

The science is pretty straight forward....power falls off according to the inverse square law. This is why laser cutters work well at relatively manageable power levels....they’re short range tools.

Not the same thing ....laser cutters power requirements <<<<<< defensive laser system.

Only at extremely short distances. The further away the laser gets the less efficient it becomes due to dispersion and absorption. If anyone needs an example of the challenges with militarizing lasers, do a search on the YAL-1.