Apart from the insane amount of power required to use lasers as propulsion in this way, they also require a camera, computer, interstellar communications system and nuclear power source within a mass budget of a few grams. It's complete science fiction.

Literally everything in this area starts out as science fiction. I think the general idea of sending lots of small craft is a good idea. It would be great to hear from the people building these things which parts are not possible currently.