Communications: Single-mode fibers outperform multimode cables: Successful field trials and imminent commercial use stem from high capacity and the need for fewer repeaters

While the world is still marveling at optical-fiber communication, the second generation of optical-fiber technology is upon us. Single-mode optical-fiber systems are being demonstrated not only in laboratories but in field trials, and they are vastly outperforming their predecessors, the multimode fiber-optic systems.