Figure 2

Dispersion curves for SPPs at air/metal and metal/glass interfaces, respectively. Red and blue star symbols represent the phase matching condition due to the anomalous diffraction for RCP and LCP, respectively. Green star symbols, which are symmetrically located, corresponds to +1 and −1 ordinary diffraction orders. LCP, left-handed circular polarization; RCP, right-handed circular polarization; SPP, surface plasmon polariton.