Seminar Talk
Abstract
Polaritons, hybrid light–matter excitations, offer a powerful route to control light at scales far below its wavelength. This enables strong confinement, enhanced interactions, and new device functionalities in photonic systems. These modes can be probed using complementary far-field and near-field techniques, providing access to both momentum-space dispersion and real-space propagation. In this talk, I will present our work on polaritonic metasurfaces, focusing on surface phonon-polariton (SPhP)-based moiré-engineered platforms in silicon carbide modified by dielectric overlayers. The introduction of controlled lattice mismatches leads to emergent mode interactions in these systems. Furthermore, these systems achieve highly efficient, tunable, and broadband polarization conversion effects, revealing new ways to tailor light–matter interactions and pointing toward compact, adaptive mid-IR photonic solutions. Additionally, I will also highlight how scattering-type scanning near-field optical microscopy (s-SNOM) enables direct visualization of polariton propagation in complex heterostructures, including exciton–plasmon polaritons in 2D heterostructures. Finally, I will discuss future directions for reconfigurable polaritonic metasurfaces and the emergence of topological field textures, such as optical skyrmions, as a pathway to robust, tunable photonic functionalities.