Hybrid Ray–Wave Modeling of Power Propagation in Dual-Core Optical Fibers

Abstract

The rapid development of high-capacity optical communication systems has led to increasing interest in dual-core optical fibers (DCOFs) due to their potential for high data throughput and reduced crosstalk. Accurate modeling of power propagation in such fibers remains challenging because traditional ray-tracing methods, while computationally efficient, fail to capture modal interference effects, whereas wave theory approaches provide detailed field distributions but are computationally expensive for long fibers or complex geometries. In this study, we propose a hybrid Ray–Wave modeling approach that combines the strengths of both methods to accurately simulate power propagation in dual-core fibers. The hybrid model first employs ray-tracing to simulate the trajectory of light rays, accounting for total internal reflections and geometric dispersion. These results are then used to initialize wave-based simulations for detailed computation of inter-core mode coupling and interference patterns. The method was applied to a standard dual-core fiber with core diameters of 8 µm, core-to-core separation of 25 µm, and a cladding diameter of 125 µm, operating at wavelengths of 850 nm, 1310 nm, and 1550 nm. Simulations demonstrated that the hybrid approach accurately predicts power transfer between cores, showing a maximum inter-core crosstalk of –23 dB at 1550 nm, consistent with theoretical expectations. In comparison, pure ray-tracing overestimated power leakage by up to 12%, while wave-only simulations required approximately 4× more computation time for fibers longer than 1 km. Validation was performed through cross-comparison with conventional models, demonstrating that the hybrid method reduces computation time by approximately 65% while maintaining <5% deviation in predicted power distribution. The results also indicate that the hybrid approach is particularly effective in regimes where the normalized frequency (V-number) exceeds 2.4, corresponding to weakly coupled modes in each core. This work provides a practical and efficient framework for modeling dual-core fiber propagation, bridging the gap between geometric optics and wave optics. It enables designers to predict modal behavior, inter-core crosstalk, and dispersion with high accuracy while minimizing computational resources. The approach is easily extendable to multi-core fiber systems and can be integrated with experimental measurements for enhanced design validation. Overall, the hybrid Ray–Wave method represents a promising tool for next-generation fiber optic communication systems, offering both speed and precision.