Design of surface plasmon polariton enhanced nanoantennas

The work was devoted to the design of advanced plasmonic nanoantennas based on numerical investigation of Surface Plasmon Polariton resonances in noble metal nanoparticles. Their dependence on the nanoparticle shape and size is investigated for an efficient manipulation by SPP strength and excitation wavelength. Local near-field plasmon effects and the impact of SPPs on the directivity of emission in far-field are analyzed simultaneously by means of a boundary integral equation approach. Various particles including the shapes with gaps and sharp tips were investigated in order to select the geometries which permit achieving of strong near-field enhancement. The investigation of crescent moon structures demonstrated the possibility of additional field enhancement because both a gap and sharp tips are realized at the same time. Analysis of all considered noble-metal nanoparticles revealed a mechanism of efficient manipulation by SPPs leading to the design of several highly optimized optical nanoantennas.