That is (almost*) the same as focusing a laser on the target with a very large lens - a highly divergent beam is only dangerous near the focus. Some laser processing machine developers make their machines eye-safe that way, if you're half a meter from the focus, the remaining radiance is low enough to not be caught by the laser safety norms anymore (there is a very low limit to which radiance is still considered class 1, after that it's not considered a laser according to the norm). But to make a highly divergent beam, you need large aperture optics.
* you'd need to have very good optics and optomechanics on each laser to make the spot small enough - the smaller optics on each smaller laser would make the spot worse than one created with a single large lens, unless the single lasers are actually from a single coherent source
That would depend on the distance you want to fry moskitos at, if you want to burn them at meters, you need a larger aperture to get a similar divergence angle as with cm.
That is (almost*) the same as focusing a laser on the target with a very large lens - a highly divergent beam is only dangerous near the focus. Some laser processing machine developers make their machines eye-safe that way, if you're half a meter from the focus, the remaining radiance is low enough to not be caught by the laser safety norms anymore (there is a very low limit to which radiance is still considered class 1, after that it's not considered a laser according to the norm). But to make a highly divergent beam, you need large aperture optics.
* you'd need to have very good optics and optomechanics on each laser to make the spot small enough - the smaller optics on each smaller laser would make the spot worse than one created with a single large lens, unless the single lasers are actually from a single coherent source
To fry a mosquito, you don't need an awful lot of energy. That means you don't need awfully big lenses to keep it human safe away from the focus.
That would depend on the distance you want to fry moskitos at, if you want to burn them at meters, you need a larger aperture to get a similar divergence angle as with cm.
it is not easy