KAIST Integrated Metaphotonics (KIM) Group

We develop novel physics-driven approaches for photonic integrated circuits (PICs) to overcome key limitations of current technologies, including scalability, noise, loss, and fabrication sensitivity. Subwavelength Gratings (SWGs) / Metaphotonics [1-4]: We utilize anisotropic subwavelength grating (SWG) metamaterials to engineer light confinement beyond conventional index-guided approaches. This enables scalable PIC architectures with suppressed crosstalk, improved extinction ratio, and reduced noise. We demonstrated extreme crosstalk suppression with record-high coupling lengths (>500× improvement over conventional waveguides). Exceptional Points (Non-Hermitian Photonics) [5-6]: We explore non-Hermitian photonics based on exceptional points (EPs), which enable non-conventional wave phenomena inaccessible in Hermitian systems. In particular, we demonstrated passive EPs in integrated waveguides, revealing unconventional wave penetration and spatially uniform energy dissipation. Topological Photonics [7]: We investigate topological photonic structures to achieve robust light transport in PIC platforms. These approaches aim to enhance fabrication tolerance and device stability by leveraging topology-protected properties. These efforts establish next-generation PIC device innovations beyond conventional design paradigms. We investigate nonlinear and quantum optical phenomena enabled by high-Q integrated photonic platforms, with a focus on dispersion-engineered microresonators for on-chip frequency comb generation. Microcombs and Dispersion Engineering [1-4]: We develop integrated microresonators with tailored dispersion to enable efficient and broadband frequency comb generation. We demonstrated dispersion control using concentric resonator geometries and multimode coupling