Abstract

Submicroscopic metal particles enhance the coupling between the dipole of a molecule and an incoming light field by resonantly light-field driven plasma oscillations [1]. By this mechanism enhanced absorption [2], enhanced fluorescence [3] and photochemistry [4] is explained. Such metal particles let also expect an influence on the intermolecular energy transfer between donor and acceptor chromophore molecules which takes place by electrodynamic dipole-dipole interaction [5]. A schematic sketch of the energy levels and transitions in the system, donor-acceptor-metal particle (silver islands film) is shown in fig. 1. A reduction of the transfer efficiency (transition D-A) can be expected since the donor’s deexcitation rate is enhanced by the fact that the dipole of the excited donor molecule drives a plasma oscillation in the particle (transition D - M) and this process competes with the direct donor-acceptor transfer. On the other hand, an additional donor-acceptor energy transfer can be expected if the acceptor molecule is in the enhanced neat’ field of the donor-driven particle plasma oscillation (transition M-A).

© 1988 Optical Society of America