We aim at high-quality semiconductor photonic nanostructures including photonic crystals. Using these photonic nanostructures, we explore the fundamental physics of light-matter interactions and their applications to novel photonic devices such as low-threshold nanolasers, single photon sources, and quantum information devices. We are also developing diamond-based nanophtonics towards quantum information applications.

The electromagnetic environment in photonic nanostructures is significantly modified from that in free space, resulting in diverse intriguing phenomena in light-matter interactions. We investigate the fundamental physics of light-matter interaction in photonic nanostructures, which includes quantum optics, nonlinear optics, and solid-state cavity quantum electrodynamics (Cavity QED).

Similar to electrons, photons can have various kinds of angular momentum, which induce exotic optical phenomena in nanostructures.
We study the basics of angular momentum of light and optical spin-orbit interaction in photonic nanostructures. In particular, we aim to realize unique nanophotonic devices based on the optical spin-orbit interaction including spin-photon interfaces, unidirectional light emitting devices, and on-chip optical Skyrmion generators.

Topological photonics, which is an emerging filed in photonics, is one of research topics in our group. The concept of topology can provide a novel route for realizing optical devices with unprecedent functionalities. We are developing semiconductor-based topological nanophotonics based on our photonic crystal technology. We have demonstrated the world-first topological nanocavity laser. We have also proposed topological slow-light waveguides and have demonstrated them in semiconductor platform.