文摘
We report the realization of two-dimensional optical wavelength demultiplexers and multiports for surface plasmons polaritons (SPPs) basedon plasmonic crystals, i.e., photonic crystals for SPPs. These SPP elements are built up of lithographically fabricated gold nanostructures ongold thin films. We show by direct imaging of laterally confined SPP beams in the visible spectral range by leakage radiation microscopy thatSPPs of different wavelengths are efficiently rerouted into different directions. In addition we demonstrate the generation of three output SPPbeams from one input beam.