Optical systems that employ concentric multi core fibers (MCFs) are discussed. Some of the systems discussed are based on the use of a concentric MCF that has a single mode core, capable of carrying a broadband data signal, and a multimode core, which carries optical signals that do not require as high a bandwidth as the broadband data signal. In one embodiment, the multimode core carries system management data. In another embodiment, the multimode core carries a high power optical signal that provides remote power. In another embodiment, the multimode core carries a pump signal for a downstream fiber amplifier. In yet another embodiment, the multimode core carries an optical signal, for example visible light, that can be used to verify connectivity.