Vectorial finite element BPM scheme applied to coupled leaky waveguide

In this paper, an efficient finite-element formulation for dielectric media with transverse anisotropy is applied to the analysis of polished-type optical fiber couplers. The method uses triangular elements in the discretization and perfectly matched layers are used as absorbing boundary. In this case we assume that two cores are curved in a parabolic shape, and between them a leaky waveguide with an index-matching liquid layer is included. The distance between cores is variable parameters. Due the inclusion of leaky waveguide the coupling distance reduces drastically.