I’ve been watching quite a few Star Trek episodes on Pluto TV for the first time. I’m wondering about phasers—not lasers—and how lasers, in general, aren’t visible from the side. However, could an energetic enough gamma laser become visible from the side due to electron-positron pair production? For instance, if a gamma photon interacts with the cosmic background radiation, the resulting electrons and positrons might interact with other gamma photons. Most of the resulting radiation would be annihilation-related and not visible, but could there still be some kind of glow? Am I thinking about this correctly?