Demonstration of orbital angular momentum (OAM) fiber amplifier in data-carrying OAM-division multiplexing and wavelength-division multiplexing (WDM) system

We demonstrate an orbital angular momentum (OAM) fiber amplifier and evaluate its performance in an OAM and wavelength multiplexing system. The small signal gain is up to 19 dB from 1530 nm to 1565 nm. The OSNR penalties at a BER of 2e-3 are less than 1.8 dB for all channels.