RHOMBIC SILVER NANOPARTICLES ARRAY-BASED PLASMONIC FILTER

Abstract

A plasmonic filter applied in visible regime is proposed. A method using discrete dipole approximation (DDA) to aid design parameters of rhombic Ag nanoparticle array is adopted for the filter design and optimization on the basis of computational numerical calculation. Influence of the particle parameters such as thickness, period and effective index of medium around the particles on the extinction spectrum is studied using the DDA-based computational analysis. The calculation results show that the thickness ranging from 35 to 45 nm and the period ranging from 350 to 560 nm are the better geometrical parameters of the rhombic Ag nanoparticle array. Considering the nano-fabrication condition, 40 nm thickness and 440 nm period were selected and fabricated using nanosphere lithography (NSL) technique. The experimental results demonstrated that the measured spectrum is basically in agreement with the theoretical spectrum derived by the DDA calculation.