Design and analysis of annulus core few mode EDFA for modal gain equalization

TL;DR

This paper introduces an annulus core few-mode erbium-doped fiber amplifier designed to achieve low differential modal gain across multiple mode groups, enhancing space division multiplexing in optical communications.

Contribution

It proposes a novel annulus core FM-EDF with extra annulus doping, demonstrating reduced DMG for multiple mode groups through simulations.

Findings

Achieved less than 2.2 dB DMG over C-band for 4-mode groups.

Extra annulus doping effectively reduces DMG of higher order modes.

The proposed EDF is suitable for SDM-based optical fiber systems.

Abstract

Few-mode fiber amplifier is widely under study to overcome the issue of internet traffic in optical communication. This article proposes annulus core few-mode erbium doped fiber (FM-EDF) with annulus or extra annulus doping for amplification of the LP01, LP11, LP21, and LP31 signal mode groups with low differential modal gain (DMG). Our simulations confirm that extra annulus doping helps in reducing DMG of higher order mode groups. We have achieved less than 2.2 dB DMG over C-band for 4-mode groups using extra annulus doping. The proposed EDF would be useful for space division multiplexing (SDM) based optical fiber communication system.