A 5-Mode Erbium Doped Fiber Amplifier for Mode Division Multiplexing Transmission
01 January 2015
We describe a few mode erbium doped fiber amplifier with ring-doped Erbium doping profile fiber and optimized optical setup amplifying LP01, LP11 and LP21 modes simultaneously. Spectral and modal gain distribution is characterized as well as modal crosstalk. We study gain evolution of every mode in several configurations, changing the input power or the number of injected modes. The gain is above 13dB for all modes and its differential modal gain is lower than 5.7dB across the whole C-band with a 3.5m long erbium doped fiber when using a pump at 630mW. As a proof of concept, we transmit up to five modes carrying each a PDM-QPSK signal at 32Gbd through this amplifier.