One of the things that makes lasers so effective is that their photons' peaks and valleys start out in phase with each other. However, all lasers have something called "coherence length," which is the distance that the photons stay in phase. Some, like diode lasers, only stay in phase for a few centimeters while others, like HeNe lasers, might stay coherent for meters. The unspecified solid state lasers, possibly Nd:YAG, would also lose effectiveness over long distances.