Phase‐Transition Photonic Brick for Reconfigurable Topological Pathways

Abstract Topological photonic insulators serve as highways for light propagation, enabling photons to be transported with topological protection and enriching the understanding of light‐matter interactions. However, the prohibitive fabrication and non‐reconfigurable functionality of current topological photonics seriously hinder its practical applications. Here, a revolutionary concept of phase‐transition photonic brick is theoretically proposed and experimentally demonstrated, which can be regarded as an ideal building block to develop reconfigurable highways for light propagations. The proposed modular photonic brick not only integrates the inherent benefits of both passive and active topological photonics, but also offers previously unattainable superiority, including flexible scalability, deformability, detachability, and recyclability. Leveraging these benefits, this work provides a groundbreaking topological platform that balances the reconfigurability, multifunctionality, low electrical energy consumption, and low device fabrication cost. By unlocking the potential of recyclable photonic bricks, the work represents a significant step toward realizing the extensive and sustainable practical applications of topological photonics in information processing, computing, communications, and beyond.