Coupling properties are significantly affective when the three cores of a photonic crystal fiber are identical or non-identical, we analyze this numerically using COMSOL Multiphysics software 5.5 to gain insight into the nature of the coupling between these cores. A non-identical core produced by a slight mismatch in the propagation constants which are sufficient to suppress coupling between the cores or may strengthen the coupling between the cores because they sometimes have equal propagation constants. By manipulating the central core diameter (increase or decrease) compared to the diameter of the other cores can limit the strength of the coupling between the cores, the coupling efficiency and the coupling length of the cores become decreasing. Introducing anisotropy in three core diameters resulting in the modes of these cores are isolated in a certain region of the array of photonic crystal fiber, as a result, the coupling is suppressed between the modes of cores at the wavelength 1064nm while some coupling appears between modes of the cores in the wavelength 1550nm where the coupling coefficient is evaluated as a function of wavelength. The coupling between three cores reveals novel characteristics more than two cores and this useful for Multiplexers and Demultiplexers applications
ا.م .د. ميامي عبد اللطيف محمد | Asst. Prof. Dr. Miami Abdulatteef Mohammad | 4619