Theory of Active Hyperbolic Metamaterials and SPASER Action

The development of a comprehensive theoretical framework for the analysis of two prototypical hybrid plasmonic systems is suggested. First, Hyperbolic Metamaterials (HMMs), i.e., structures consisting of alternating layers of plasmonic and dielectric materials, promise broad-band enhancements of the optical density of states. In turn, this leads to complex radiation dynamics of embedded active materials. The ultimate optical performance of HMMs is determined by nonlocal effects of the plasmonic constituents as well as the details of their microstructure. Such active HMMs represent ideal hybrid structures that can be fabricated by alternating layers of doped transparent conductive oxides (TCOs) with layers of conjugated polymers or dielectric matrices with embedded conjugated molecules. Here, the TCOs act as plasmonic systems whose properties can be tuned via the doping levels and the conjugated systems provide the active dielectric constituent. Second, the SPASER (Surface Plasmon Amplification by Stimulated Emission of Radiation) is a nano-scale generator of coherent plasmons. Therefore, SPASER action requires the simultaneous presence of a resonant plasmonic system and an optical gain medium. As a result, the SPASER properties strongly depend on the coherent interplay of optical fields and electronic excitations in both, the metal and the active material. Such systems can be realized via metal core/conjugated organic shell hybrid structures. In cooperation with experimental partners, this theoretical framework will be applied to investigate the complex dynamics in these two prototypical systems.