Finite Difference Beam Propagation Method Applied to Photonic Crystal Fibres

University of Nottingham (UoN) and National Institute of Telecommunications (NIT) in Warsaw have a well established cooperation in the field of the numerical methods for the modelling of the photonic structures in the framework of COST Pll project. Both research groups are using frequency domain Finite-Difference Beam Propagation Method (FD-BPM) for the calculations. The algorithm developed at the University of Nottingham is a semi-vectorial, real distance ADI (Alternating Direction Implicit) Pade(l,l) algorithm with the Perfectly Matched Layers (PML) boundary conditions. Program developed at the NIT is a full-vectorial, real distance paraxial algorithm with the Transparent Boundary Conditions (TBC). This paper presents some of the results obtained in UoN and NIT and describes the disadvantages of the FD-BPM methods applied to Photonic Crystal Fibres (PCF).