Two-LP-Mode Six-Core Cladding Pumped EDFA With High Pump Power Density

We report the design, fabrication, and evaluation of a cladding pumped two-LP-mode six-core moderately coupled erbium-doped fiber (EDF) amplifier. In this study, we show that moderately coupled multi-core EDF can realize a high pump power density in a cladding by allowing core-to-core power coupling. We also experimentally evaluate the amplification characteristics and confirm an average mode-core gain of 18 dB, a differential mode-core gain of 4 dB, and an average noise figure of 7 dB in the C-band. Moreover, we confirm an average mode-core gain of 15 dB, a differential mode-core gain of 5 dB, and an average noise figure of 7.5 dB in the L-band.