Plasmonic nano-structures for opto-mechanical and sensing applications

Abstract

We simulate the spectral properties of simple plasmonic nanoparticles (NPs), which we have fabricated with electron beam lithography (EBL) and lift-off, with or without nano-grooves milled by ion-beam lithography (IBL). We estimate the NP behaviour under laser illumination using 3D finite difference time domain (FDTD) simulations, showing that simple non-chiral NPs can generate torque from circularly polarized beams and emit optical vortices via spin-orbit coupling. We demonstrate numerically the position and intensity control of field enhancement hot-spots in chiral NPs illuminated by optical vortex, by combining spin/orbit momentum and NP chirality.