Tailoring the directional dependent emitter interaction based plasmonic antenna character of Ag–Au heterodimer

Abstract

Based on the concept of optical nanoantennas, light-matter interaction between metal heterodimer (Ag and Au spherical nanoparticles) and single dipole emitter system are numerically simulated utilizing a MATLAB toolbox MNPBEM17 based on boundary element method (BEM). The precise position and orientation of the dipole emitter systematically controls not only the (non)radiative losses, but also the efficiency of excitation (absorption) and respective emission processes in the vicinity of the plasmonic optical antenna system. The overall (non)radiative decay rates and associated surface charge distributions help estimate the spatio-directional dependency of dipole emitter emission, analogous to that of the SERS enhancement. Furthermore, the Poynting vector analysis of our present hybrid plasmonic antenna system effectively assesses the flow of electromagnetic energy, thus accounting for improvement in both near- and far-field propagation modes. The calculation of Purcell factor and coupling strength along with quantum yield evaluate the detailed optical response of a nanoantenna characteristics simultaneously based on the dipole emitter position and orientation, offering better scope for understanding the underlying mechanisms governing such intriguing interactions in complex geometries as well.