Plasmon resonance excitation and near-field manipulating in gold nanopyramid arrangements at the telecommunication spectrum

Abstract

In this work, we investigated the optical characteristics of a gold nanopyramid with certain geometrical dimensions to generate surface plasmons inside it at the near infrared region. The approximate geometrical sizes for all of the revisable dimensions have been computed based on the position and peak of the plasmon resonance at wavelength 1550 nm. The influence of absorption and scattering of light as dissipative and lossy components on the optical response of the non-spherical configuration have been discussed numerically. Employing the examined pyramid in a chain, we measured the quality of the near-field coupling between series pyramids, and the optical properties of the provided plasmon waveguide have been determined. Moreover, the group velocity of guided waves and transmission loss factors along the nanostructure have been quantified as υgT=0.23c0, υgL=0.41c0 and γT=3 dB/452 nm, γL=3 dB/312 nm for transverse and longitudinal polarization modes, respectively. The finite-difference time-domain method has been utilized as a major solution to extract the optical properties of the proposed configurations.