Theoretical and experimental investigation of strongly localized plasmons on triangular metal wedges for subwavelength waveguiding

Abstract

We report numerical analysis and experimental observation of strongly localized plasmons guided by a triangular metal wedge. Dispersion and dissipation of such wedge plasmons are analyzed using the finite-difference time-domain algorithm. Experimental observation is conducted by the end-fire excitation and near-field detection of the predicted plasmons on a 40° silver nanowedge. Good agreement with the theoretically predicted propagation distances is demonstrated. Differences between the theoretical and experimental field distribution are explained by insufficient resolution of the near-field optical probe.