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arXiv · 2610.31004

Efficient Modeling of 3D-Printed Freeform Waveguides with a Transformation Optics-Based Beam Propagation Method

Sina Foroutan-Barenji·Jonas Krimmer·Stefan Singer·Christian Koos·Wolfgang Freude
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Abstract

An efficient numerical method is introduced for simulating wave propagation in 3D-printed freeform waveguides, referred to as photonic wire bonds (PWBs). This approach integrates transformation optics (TO) with curvilinear meshing to map the original 3D freeform PWB structure onto a straight waveguide, which possesses anisotropic material characteristics. The resulting waveguide is then analyzed using an anisotropic full-vectorial beam propagation method (BPM). To validate the performance and effectiveness of the proposed TO-BPM algorithm, a comparison is made with the finite-difference time-domain (FDTD) technique. Our approach reduces the simulation time by more than two orders of magnitude, depending on the degree of trajectory bending, in combination with a mean absolute percentage error (MAPE) of 3.9% in power transmission simulation relative to the FDTD.

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Sina Foroutan-Barenji, Jonas Krimmer, Stefan Singer, Christian Koos, Wolfgang Freude. 2026-10-22. Efficient Modeling of 3D-Printed Freeform Waveguides with a Transformation Optics-Based Beam Propagation Method. https://doi.org/10.1364/oe.610722

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