"At the nanoscale, light and matter engage in a fascinating dance, where the ordinary rules of optics break down, giving rise to extraordinary phenomena. In this realm, the interaction of photons with nanostructured materials can lead to the formation of "polaritons"—quasi-particles that blend the properties of light and matter. These polaritons, created when photons couple strongly with excitations in matter like excitons, phonons, or plasmons, offer unprecedented control over light propagation, confinement, and manipulation at dimensions much smaller than the wavelength of light. This opens a gateway to novel technologies in nanophotonics, quantum computing, and ultra-sensitive sensors, where we can harness the hybrid nature of light-matter interaction to push the boundaries of science and innovation. "