Unusual splitting behavior of the dispersion of surface polaritons in gratings of different symmetry, amplitude, and profile.
The splitting behavior of the dispersion relation of plasmonic surface polaritons (surface plasmons) in silver gratings in the region of vanishing lateral momentum is investigated. The reflectivity of light was measured as a function of the amplitude and the shape of the grating. Although for nonsinusoidal gratings a splitting into low- and high-frequency branches of the dispersion relation is found, for sinusoidal gratings a splitting in lateral momentum is found. These phenomena are also found numerically by the use of a transfer matrix method.
B
B
Fischer
T M
TM
Fischer
W
W
Knoll