Finite difference time domain (FDTD) calculations of surface plasmon resonance of different size and shape metallic nanoparticles

Abstract

In this work we employ the Finite Difference Time Domain (FDTD) method to calculate the optical spectra and the intensity of local electromagnetic field at the surface of different size, shape and assembling configuration of nanoparticles (NPs) with a view to optimize their sensing activity. We first consider gold nanospheres of 20 nm diameter where analytical solutions are available for comparison. The other shapes we consider include gold nanorods and silver nanoprisms which are particularly important for applications, because they allow tuning the plasmon resonances across the whole visible and near infrared range. The theoretical spectra are compared with experimental data from synthesized samples in our laboratory.