Topological photonics

Topological photonics is an emerging field that applies concepts from topological phases of matter to control light in novel ways. Engineering photonic structures with nontrivial topological properties enables robust light transport that is immune to defects, scattering, and disorder. This robustness opens pathways for developing stable photonic devices, such as waveguides and lasers, with applications in quantum communication and optical technologies. We have pushed the boundaries of topological photonics by experimentally realizing higher-order topological corner states in photonic waveguide lattices. We employed femtosecond laser writing in glass to fabricate two-dimensional breathing kagome lattices that support robust light localization at corners—even in the presence of defects. This work not only showcases the versatility of engineered photonic structures but also could open up new pathways for compact, resilient photonic devices.