Gold hollow nanodomes arranged in hexagonal lattices support surface plasmon polaritons (SPPs) propagating at air-Au interface. The cross-sectional heights of the continuous and hierarchical hexagonal nanodome arrays can be altered by a simple thermal treatment, and the change in nanodome size leads to a significant linewidth narrowing of plasmon resonance because of reduced scattering loss. Taking the variation in the SPP intensities into account, the surface modulation depth is found to be around 100 nm for achieving a longer propagation length of SPP.
Keywords: hollow nanodomes; resonance linewidth; scattering cross section; surface modulation depth; surface plasmon polaritons (SPPs).