Good question, probably depends a lot on how much energy actually makes it to the target some distance away. And then how much is actually absorbed. Probably depends more on the power density then, rather than total power?
Can't imagine they get a very small spot at multiple km unless they use gigantic lenses or multiple independent laser focused on the same spot
Can't imagine they get a very small spot at multiple km unless they use gigantic lenses or multiple independent laser focused on the same spot