Optical absorption resonances of dye-coated silver-island films.

We have used Mie theory to account for the features of the transmission spectra of dye-coated silver-island films. The unusual behavior of the spectra arises from the effect of the dispersion and damping of the optical response of the absorbing coating on the structural resonances of the silver islands. Our modeling indicates that the power dissipation in the dye coating is enhanced compared with the dissipation of dye deposited on a nonresonant structure. These results help elucidate the excitation mechanisms of Raman and fluorescent emission of adsorbates at rough silver interfaces.