Topological Silicon Photonics

The field of topological photonics has seen tremendous and wide‐ranging developments in recent years. Evolving from the broader field of topological insulators, topological photonics systems today harness a variety topological phases. These include the Su–Schreifer–Heeger, quantum Hall, quantum valley Hall and quantum spin Hall topologies. Importantly, the latter two generate edge states with opposite group velocities and opposite spin, respectively, allowing unidirectional light propagation and advanced photonic routing to occur. Amongst these exciting developments is a subset of advancements made in topological silicon photonics, which could potentially lend its appeal to complementary metal–oxide–semiconductor (CMOS) photonics applications, including telecommunications, data communications, quantum photonics, future exascale supercomputers, photonic neuromorphic computing, and infrared sensing. The fundamental underpinnings of these topological phases lead to interesting features, including chirality, scatter‐free light propagation around sharp bends, and importantly topological protection against defects, disorder, and scattering. This topological protection may be harnessed toward tunable light propagation, photon‐pair generation, quantum spatial entanglement, robust photonic routing, and beyond. Herein, the recent advancements made in the burgeoning field of topological silicon photonics are discussed.