The object is to provide an optical repeater, a manufacturing method of an optical repeater, and a relay method of an optical signal that can achieve a redundant configuration for a failure of a light source outputting an excitation light with a simple configuration. Light sources output lights. The optical amplification units amplify optical signals using excitation lights. An optical distribution unit branches the lights output from the light sources into two branched lights and distributes the branched lights in such a manner that each of the optical amplification units receives the branched light branched from the lights from two different light sources as the excitation light.