Wavelength tuning of surface plasmon resonance using dielectric layers on silver island films

A simple and effective method was demonstrated to tune surface plasmon resonance (SPR) wavelength of silver island films by introducing a dielectric medium to vary interisland dielectric constant. The medium, either overcoating or sandwiching the silver islands, can make a dramatic effect on the tunability. We had extended the SPR wavelength tunability of standard silver island film substrates from 432 to 482 nm to 506 to 1310 nm using two dielectric layering methods. A generalized Maxwell-Garnett theory was applied to interpret these results. (C) 2003 American Institute of Physics.