Erbium-ytterbium co-doped photonic crystal fiber amplifier supporting amplification for orbital angular momentum

Abstract

In order to reduce the loss in orbital angular momentum (OAM) long-distance communication systems, an OAM erbium-ytterbium co-doped fiber amplifier (OAM-EYDFA) based on photonic crystal fiber (PCF) is proposed and investigated for the first time in this work. We set up a three-dimensional electromagnetic field model of the PCF in Comsol and solved it by the finite element method. Then, we designed a three-dimensional model of the OAM-EYDFA based on the proposed PCF using Comsol and MATLAB. The results reveal that the proposed OAM-EYDFA has a flat-high gain of about 47 dB, a differential mode gain of lower than 0.3 dB and a noise figure of lower than 3.4 dB. Compared with existing studies, its gain is increased by at least 25 dB, and other properties are also improved. The proposed OAM-EYDFA can provide a reference for OAM-based long-distance communication systems.