Ultrafast light dynamics in plasmonic metastructures*

Coherent and incoherent nonlinear optical effects play important role in photonics, laser physics and quantum optics. However, nonlinear optical applications are limited by the available choice of naturally occurring materials and their generally weak nonlinear response. Weak nonlinearity of conventional materials can be enhanced by their nanostructuring or through metamaterial approach. Plasmonic and dielectric nanostructures provide numerous opportunities for designing optical response in both linear and nonlinear regimes. Combining dissimilar plasmonic and dielectric materials in one nanostructure offers additional prospects for devising optical properties and achieving functionalities not attainable otherwise. Here, we will discuss hetero-nanostructures for tailoring hot-electron dynamics, plasmonic nonlinearities, and ultrashort pulse manipulation. Going beyond traditional field enhancement effects, we show how the introduction of additional hot-electron relaxation pathways, anisotropy and nonlocality allows to accelerate of decelerate the temporal response of nonlinear optical effects in plasmonic nanostructures. The metamaterial designs for controlling ultrafast pulse propagation with metamaterials will also be discussed. Ultrafast optical and electronic processes in nanostructured materials may find applications in nonlinear photonics, photocatalysis and development of time-varying media.