LONG-RANGE ENERGY TRANSFER VIA HYBRID PLASMONIC-PHOTONIC STRUCTURES

Dipole-Dipole resonant coupling is a common mechanism for short-range energy transfer (ET), typically occurring over a range of several nm. Surface plasmons (SP) may enhance ET and indeed, it was demonstrated that SP on opposite sides of a thin metallic film may extend the ET range by carrying the donor emission to the acceptor [1,2], when both are located close to the metal. We demonstrate that a metallic microcavity, designed to couple plasmonic and intra-cavity photonic modes, can further extend the ET range, exceeding a distance of 100 nm. In our experiments we are taking advantage of the unique intensity distribution inside the specifically-designed, hybrid photonic-plasmonic microstructure for mediating ET between a donor overlay (Fluorescein), to intra-cavity acceptor molecules (Rhodamine-B). The ability to tailor the dispersion of this hybrid system, by tuning the dimension of the various layers, presents an innovative and flexible ET mechanism, which allows selecting any desired pair of molecules, even if their spectral overlap is small, in contrast to previous works using plasmonic or photonic modes for energy transfer. Furthermore, such a mechanism may find potential applications in photovoltaics, where energy should be collected from the outside and efficiently conveyed into the photovoltaic cell. References [1 P. Andrew, W. L. Barnes, "Förster Energy Transfer in an Optical Microcavity," Science 290, 785 (2000). [2] E. Collini, F. Todescato, C. Ferrante, R. Bozio, and G. D. Scholes, "Photophysics and dynamics of surface plasmon polaritons-mediated energy transfer in the presence of an applied electric field," J. Am. Chem. Soc. 134, 10061 (2012).