Hai Son Nguyen is an experimental and theoretical physicist specialized in nanophotonics, quantum optics and condensed matter physics. He is interested in both fundamental research and technological applications. His current research focus on the theme of light-matter interaction in nano and microstructures at the sub-wavelength scale, with three main research activities: - Novel concepts of optical lattice and metasurface: light confinement in moiré structures, non-hermitian photonics and topological photonics. - Perovskite-based emitting devices: implementation of nanophotonic design to improve performance of perovskite LEDs and lasers in the weak coupling regime; and to study exciton polariton features in the strong coupling regime. - Single photon emitters in/on silicon substrate at telecom wavelength band: Engineering far-field pattern of single photon emission from III-V quantum dots in nanowires grown on silicon substrate; and enhancement of single photon source based on G-centers in silicon photonic crystal nanocavity and waveguide.