TY - JOUR A1 - Lohmeyer, M. A1 - Shamonin (Chamonine), Mikhail A1 - Hertel, P. T1 - Boundary conditions for the finite difference beam propagation method based on plane wave solutions of the Fresnel equation T2 - IEEE Journal of Quantum Electronics N2 - Each particular implementation of the beam propagation method (BPM) requires a special procedure allowing for radiation to leave the computational window. We propose a new approach to constructing the finite difference schemes of the BPM at the boundary of the computational window. These schemes are independent of the computed fields and allow for a similar treatment of both interior and boundary points. The new approach can be further improved by correcting the field values at the boundary points according to Hadley's method. The algorithm is easy to implement for both two- and three-dimensional structures. The new method considerably reduces computation times because the propagation matrices remain constant in longitudinally invariant sections, thus avoiding repeated LU-decompositions. The basic idea-establishing the finite difference scheme such that locally exact, approximate, or plausible solutions are recovered-may be of interest for other efforts to solve partial differential equations by the finite difference method. KW - Boundary conditions KW - Finite difference methods KW - Optical propagation KW - Matrix decomposition KW - Computational modeling KW - Refractive index KW - Maxwell equations KW - Sparse matrices KW - Partial differential equations KW - Shape Y1 - 1997 UR - https://opus4.kobv.de/opus4-oth-regensburg/frontdoor/index/index/docId/6708 SN - 0018-9197 VL - 33 IS - 2 SP - 279 EP - 286 ER -