Abstract

We report the enhancement of fluorescence from molecules located within periodic and random arrangements of metallic nanocavities. Two distinct fluorescence enhancement mechanisms exist. The first mechanism is associated with confinement within the nanocavities and results in an increase in fluorescence output by more than an order of magnitude. The second mechanism is associated only with periodic nanocavity arrangements where surface plasmon excitation occurs. The peak of the surface plasmon enhancement occurs under the condition of extraordinary transmission of the incident light, where the incident light is concentrated within the nanocavities. This effect results in an additional fluorescence enhancement by about a factor of two.

© 2003 Optical Society of America