Finite element modelling of independent core propagation in multicore photonic crystal fibres resulting from anisotropy in structure

COMSOL MULTIPHYSICS software based on the finite element method is being used to simulate the random anisotropy in diameters of the cores formed in multicore photonic crystal fibre structures, and this may affect the coupling properties between the cores' modes. Consequently, this leads to a reduction in the coupling efficiency between the cores with different structures. This anisotropy in diameters of the cores leads to the creation of a small mismatch between the modes of these cores and is sufficient to inhibit coupling. The coupling properties are affected hugely depending on the amount of the change in core diameter and increasing the number of cores coupled inside the multicore structure. We also found an improvement in the coupling efficiency when increasing the number of cores within the structure of the multicore photonic crystal fibres; otherwise, the independent light propagation of each core inside the multicore structure, with/without a little penetration with other adjacent cores. As the coupling efficiency of seven-core coupled is better than three-core, and the latter may be better than two-core in which the cores appear decoupled and independent in their propagated for the adjacent other cores. It can be considered this study a novel characteristic of multiplexing-demultiplexing applications. (paper)