Ankita Gaur

Design and Analysis of Annulus Core Few Mode EDFA for Modal Gain Equalization

A few mode (FM) fiber amplifier is widely under study to overcome the issue of Internet traffic in optical communication. This letter proposes annulus core FM erbium-doped fiber (EDF) with annulus or extra annulus doping for the 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 four-mode groups using extra annulus doping. The proposed EDF would be useful for the space division multiplexing (SDM)-based optical fiber communication system.

Gain equilization of six mode groups using trench-assisted annular core EDFA

Space division multiplexing (SDM) demands the development of the Few-mode erbium doped fiber amplifier (FM-EDFA). In this article, we propose a trench-assisted annular core EDFA using extra annulus doping for the gain equalization of six signal mode groups LP<inf>01</inf>, LP<inf>11</inf>, LP<inf>21</inf>, LP<inf>31</inf>, LP<inf>41</inf> and LP<inf>51</inf>. The simulations confirm that the trenches help in reducing the differential modal gain (DMG). Thus, the proposed configuration would be useful for SDM based optical communication system.

High-power single-mode trench-assisted EDFA

A trench assisted, 0.15-NA, effective single mode leaky Erbium Doped Fiber Amplifier is proposed for high power applications. The segmented-core of the fiber enables to achieve 783 μm2 mode area which reduces nonlinearity and increases power handling capacity of the fiber. The leakage loss of the modes is controlled by annular core segments and low index trench in the cladding. The leakage loss of the LP11 mode is 10.49 dB/m and that of the fundamental mode is 0.017 dB/m at 1530 nm wavelength. We have injected 20 mW power into each mode and have calculated the gain for 26 m length of the fiber using 250 W pump at 980 nm wavelength. The signal power in the LP01 mode is amplified to 122 W and that in the LP11 mode drops down to 5.78×10-27 W. The low output signal power in LP11 mode ensures selective single mode amplification of fundamental mode. Selective single mode amplification confirms good beam quality at the output end.

Five mode groups EDFA for Mode Division Multiplexing

We propose a few-mode EDFA for amplification of 5 mode groups with less than 2.2 dB DMG over C-band using fundamental mode pumping. The annulus core EDF is studied using annulus and extra annulus doping.

Multi-Trench-clad EDFA for High Power Amplification

A multi-trench clad EDFA with 780 µm^2 mode-area is proposed. Single-mode output is ensured by higher order mode discrimination. Output power of 90 W with differential modal gain of 40 dB has been obtained.