Demonstration of Cladding-Pumped Six-Core Erbium-Doped Fiber Amplifier

We demonstrate cladding-pumped 6-core Erbiumdoped fiber amplifiers (EDFAs) using two different pump coupling schemes: edge-coupled and side-coupled pumping, where a single multi-mode laser diode can be applied to pump all cores. Using two in-line cladding-pumped EDFAs at the input and output of a 31-km coupled-6-core fiber, we realized 465-km space-division multiplexing and wavelength division multiplexing transmission in a recirculating loop and achieved a spectral efficiency of 18 bits/s/Hz. Through side-coupled pumping, the cladding-pumped 6-core EDFA produced >18-dBm output power per core and had 6-dB noise figure across the C-band.