Modeling Fluorescence Enhancement from Metallic Nanocavities

We study the excitation and emission enhancement mechanisms for fluorescence from molecules confined within subwavelength metal apertures, or nanocavities. The variation in these enhancements with wavelength is calculated for individual round nanocavities in gold of varying diameters and dielectric environments. Enhancement peaks are associated with localized surface plasmon resonances of the nanocavity. In addition, these enhancements strongly vary with location within the nanocavity. These results should aid future work in maximizing overall fluorescence enhancement from these structures.