Cladding-Pumped Coupled 12-Core Fiber Amplifier for Energy-Efficient SDM Transmission

This paper introduces the technologies for a cladding-pumped multi-core fiber (MCF) amplifier with high power conversion efficiency (PCE) and describes the advantages and challenges associated with its application to an energy-efficient space division multiplexing (SDM) transmission system. Experimental results show that our coupled 12-core erbium-doped fiber amplifier (EDFA) has a PCE of up to 14.5% thanks to its high core-to-cladding ratio cross-sectional design and efficient pumping power launching and recycling techniques. We also discuss the impact of the PCE of a multi-core EDFA on the energy efficiency and clarify that a PCE of more than 10% has the potential to achieve lower power consumption than conventional EDFAs.