A. Ashok, Arya Arackal, G. Jacob
Nanoscience and Nanotechnology
Surface Plasmon Polaritons (SPPs) are intrinsically two dimensional excitations existing on the metal dielectric interface, which will decay exponentially with distance. In this work we studied the dependence of shape and gap of the structures on its field enhancement. Triangular structure has more electric field enhancement when compared with circle, ellipse and square, because of their sharp corners, which can make better confinement than any other structures. It has been identified the enhancement in single and double structures, in which double structures shows more field localization due to its coupling of the electric field between the structures. When the gap between two structure decreases, the dipole-dipole interaction and field enhancement increases and leads to a red shift in wavelength. In the study of ellipse we identified a double peak of resonance in longer wavelength (longitudinal resonance) and shorter wavelength (transverse resonance) due to the major axis minor axis of ellipse respectively. In triangular patterns, as the gap between the structures is less, then near field coupling is more. So the total effect is a single resonance peak irrespective of the number of resonators present in the pattern.