1D to 2D transitional structure of plasmonic crystals: fabrication and characterization

A very interesting structure that has not been explored previously is an array of “corrugated/wavy” lines; an intermediate structure between 1D grating and 2D arrays of plasmonic crystal. This novel structure is studied to fully understand the transitional effect from 1D line to 2D arrays. The changes in geometry will subsequently change the effective refractive index of the crystal hence alters the plasmonic coupling conditions. The azimuthal effect of this structure is also explored to control the SPP magnitude and propagation direction. Interference lithography (IL) technique is used to fabricate this structure. Some geometrical parameters can be controlled in order to optimize the coupling condition for SPP propagation. This will lead us to understand the fundamental geometrical contributions to the field enhancement. Comprehensive mathematical simulations that model these effects to the SPP coupling condition has been undertaken to understand the plasmonic coupling efficiency and the azimuthal angle dependence.