At the center of my small (one million star maximum) galaxy, there is an incredibly enormous light pillar, originated from a ridiculously huge super-construction. The stars orbit around the giant object as if it was a supermassive black hole. I want to justify its existence with the following:
Several light years away, the emitted beam is received in two other constructions. They are smaller by logarithmic scales, yet they consume enormous amounts of energy. They are also equipped with billions of receivers that listen to a transmission encoded within this beam.
Therefore, the pillar is a constant beam of high-energy electromagnetic waves. I have several issues with it, though:
Of course, to make it possible, the beam itself must have a wavelength of the visible light - at least this is my assumption. Am I wrong?
Redshift and blueshift are not factors here - at least I think so, as everything's orbiting around this pillar. Again, am I wrong?
Is visible light suitable for data transmission the way radio waves are? My assumption is yes, as optical cables are a thing for almost several decades now, but I'm skeptical that the same system would work in space, where light is spreading and escaping in every direction.
Is it possible at all, to have a light pillar that is visible even from light years away? Do not imagine the scale of the Milky Way, 1-100 light years are "enough" for me, in this case.
Technically, these are multiple questions but are related to the same phenomena - which is actually inspired by pulsars, so some statements regarding them might answer this question perfectly. (but fix me if I'm wrong)