Open AccessEfficient strategy to increase higher order inter-modal stability of a step index multimode fiber
Author(s) -
Aamir Gulistan,
Souvik Ghosh,
Siddharth Ramachandran,
B. M. A. Rahman
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.029714
Subject(s) - multi mode optical fiber , mode volume , optics , equilibrium mode distribution , modal , mode (computer interface) , modal dispersion , mode coupling , stability (learning theory) , fiber , mode scrambler , fiber laser , materials science , graded index fiber , photonic crystal fiber , physics , single mode optical fiber , optical fiber , radiation mode , fiber optic sensor , plastic optical fiber , computer science , machine learning , polymer chemistry , composite material , operating system
We demonstrate a novel approach to enhance the mode stability through increased effective index difference (Δneff) between the higher-order modes (LP 18 , LP 09 and LP 19 ) of a multimode fiber. Fibers with large diameters have bigger effective mode areas (Aeff) and can be useful for high power lasers and amplifiers. However, a large mode area (LMA) results in an increased number of modes that can be more susceptible to mode coupling. The modal effective index difference (Δneff) strongly correlates with mode stability and this increases as the modal order (m) increases. We report here that the mode spacing between the higher order modes can be further enhanced by introducing doped concentric rings in the core. In our work, we have shown a more than 35% increase in the mode spacing between the higher order modes by optimizing the doping profile of a LMA fiber. The proposed design technique is also scalable and can be applied to improve the mode spacing between different higher order modes and their neighboring antisymmetric modes, as necessary.