Ultrafast dynamics of nanorod-based plasmonic metamaterial and their excitonic hybrids

In this presentation we show that the recently discovered nonlocal optical behaviour of plasmonic nanorod metamaterials enables an enhanced, ultrafast, and nonlinear optical response of this hyperbolic structure. In particular, a large (80%) change of transmission through this subwavelength thick slab of metamaterial subjected to a low control light fluence of 7 mJ/cm², is observed when the conditions of non-locality are satisfied. The picosecond temporal response of the system leads to switching frequencies in the terahertz range. [1] Coupling the metamaterial to a molecular aggregate supporting excitonic excitation, leads to an hybrid material with exciton-plasmon eigenstates. [2] Ultrafast spectroscopy reveals the dynamics of the hybrid metamaterial in both strong and weak coupling regimes, demonstrating drastic differences in both their temporal and spectral dynamic response.