Reconfigurable Topological Power Router Based on Interferometric Edge States

Topological photonic crystals, particularly valley photonic crystals, offer a robust platform for controlling light propagation. However, most existing topological devices possess fixed transmission characteristics and lack real-time reconfigurability. Here, we propose a reconfigurable topological power router that overcomes this limitation. The device is a four-port structure implemented in a substrate-integrated platform, where two input ports excite topological edge states. These states interfere within a compact region, enabling dynamic control over the power distribution between the two output ports. The power splitting ratio is continuously tunable, determined solely by the relative phase difference between the input signals or the operating frequency. We present both theoretical analysis and experimental results that validate this interferometric control mechanism. This work bridges the robustness of topological transport with the flexibility of interferometry, establishing a new pathway for dynamic power control in topological circuits.