Industrial scaled MCF – Design, Fabrication and Characterization

A Fiber Modeling tool based on FEM solver COMSOL Multiphysics was developed for multi-core fibers (MCF) regarding geometrical flexibility. We performed general MCF design studies based on analytical Cross Talk (XT) model. 7-core MCF designs were developed based on commercial Ge-doped Telecom core rods. Beside the specification for XT critical parameters were the mode field diameter (MFD), dispersion behavior and leakage loss which had to be considered. Theoretical investigations regarding trench-assisted MCF to reduce unwanted XT effects are presented. Two approaches for MCF fabrication are compared: Stack-and-Draw and Drill-and-CR-insertion. A geometric analysis of the drilled cylinders serves as an intermediate quality control. A corresponding fit to the circular holes yields to a resolution of 0.025 mm for the hole center. It was shown that the deviation of axial position of each bore is < 0.2 mm/m. For all realized fibers first experimental data, including insertion - and dispersion loss, are shown and compared to the modelling results. Furthermore, a concept for coupling a single-mode VCSEL-array into the MCF is presented.