Simulation, Fabrication and Observation of Plasmonic Halos

F. Ye[1], M. Burns[1], J. Merlo[1], M. Naughton[1]
[1]Department of Physics, Boston College, Chestnut Hill, MA, USA

We present the simulation, observation and systematic study of a novel optical phenomenon, a “plasmonic halo”, wherein optically pumped surface plasmons on circular silver microcavities form confined drumhead modes that, under off-resonant conditions, transform to colorful far field radiation at their circumferential boundaries. We simulated the surface plasmon drumhead modes via COMSOL Multiphysics®, and measured their near-field profiles in the Nanonics MultiView NSOM system. We also identified various drumhead modes via investigation of the modulated transmission spectra through the halo structures. We have thus demonstrated both experimentally and theoretically that such circular microcavities integrated with perimeter step gaps can generate surface plasmon cavity modes, and modulate optical transmission/ emission through/from the device, yielding the plasmonic halo effect.