Detailed characterization of a high-gain, low differential modal gain and low gain flatness integrated FM-EDFA for multi-wavelength amplification

In this paper, an integrated few-mode erbium-doped fiber amplifier (FM-EDFA), with high gain, low differential modal gain (DMG), and low gain flatness for multi-wavelength amplification, is constructed using homemade weakly-coupled ring-core few-mode erbium-doped fiber (FM-EDF) and low insertion-loss passive components. The gain characteristics of the FM-EDFA for multi-wavelength amplification are analyzed in detail and compared with single-wavelength amplification. The experimental results demonstrate that, although multi-wavelength amplification in different modes has an impact on the gain characteristics, through simple LP