Recent attempts to understand quantum materials in terms of “topology” have led to the discoveries of new phases of matters such as topological insulator and topological semimetal phases. Such notions of topological degrees of freedom are not limited to quantum waves, but are manifested in other wave systems including photonic or phononic waves.


Our group focuses on novel topological phenomena in nanophotonic platforms such as thin-film subwavelength nanophotonic architectures, known as optical metamaterials or metasurfaces.

Thanks to their design flexibility for judiciously constructing artificial nanostructures, topological nanophotonics can provide new powerful methodologies for exploring hypothetical phenomena including non-Hermitian and subtle high-dimensional topological natures, which have not been explored in condensed-matter systems. Also, practical realizations of exotic topological natures in nanophotonic systems suggest fundamentally new states of light and potentially revolutionary applications for compact photonic cavities, robust light signal transports, and modulations.