well, an optical amplifier wouldn't do anything at all attached to a waveguide into a feed horn, in something like a 6.3 meter ku or c band cassegrain antenna d

well, an optical amplifier wouldn't do anything at all attached to a waveguide into a feed horn, in something like a 6.3 meter ku or c band cassegrain antenna design antenna aimed at a geostationary satellite... that's the job for a BUC/SSPA. You need. it needs to be RF. rf over fiber in a satellite teleport application is more about being able to separate the modem from the antenna-mounted LNB and BUC/SSPA which might be some distance away.