Large-area low-loss fibers and advanced amplifiers for high-capacity long-haul optical networks [Invited]

This paper reviews recent progress on ultra-large-area low-loss fibers for next-generation high-capacity terrestrial long-haul optical networks. The key optical fiber properties of new class fibers are described, and their impact on the transmission performance for 400 Gb/s polarization-multiplexed multilevel modulation coherent transmissions is discussed. The practical consideration of the large-area fibers, such as splicing and cabling for terrestrial transport systems, is also briefly addressed. In addition, we describe two advanced optical fiber amplifier technologies that will improve the efficiency in utilization of optical networking and reduce total system costs. The design and performance of an arrayed optical fiber amplifier using a compact ribbonized Er-doped fiber (EDF) for next-generation reconfigurable optical add/drop multiplexer nodes are discussed, and the performance characteristics of complementary Raman/EDFA, which has +70 nm bandwidth for seamless C+L-band transmissions, are described. Finally, we present the experimental demonstration of transmission of 34.6 Tb/s in 70 nm single band over 2400 km fiber.