Figure 3.

(a) At normal incidence, the transmission spectra of the 1D periodically corrugate silver film immersed into air, DI water, and several solutions of CaCl₂ at different concentrations. The spectra have been arbitrarily displaced along the ordinate for clarity and corresponding materials information areindicated by the side of each curve. (b) Dependence of the resonance wavelength of surface plasmons at the interface of silver and surrounding materials and the FoM calculated from (a). The inset shows the data point when the surrounding material is air.