Experimental demonstration of two-dimensional hybrid waveguide-integrated plasmonic crystals on silicon-on-insulator platform

Nanoscale plasmonic structures can offer unique functionality due to extremesub-wavelength optical confinement, but the realization of complex plasmonic circuits ishampered by high propagation losses. Hybrid approaches can potentially overcome thislimitation, but only few practical approaches based on either single or few element arraysof nanoantennas on dielectric nanowire have been experimentally demonstrated. In thispaper, we demonstrate a two dimensional hybrid photonic plasmonic crystal interfaced witha standard silicon photonic platform. Off resonance, we observe low loss propagationthrough our structure, while on resonance we observe strong propagation suppression andintense concentration of light into a dense lattice of nanoscale hot-spots on the surfaceproviding clear evidence of a hybrid photonic plasmonic crystal bandgap. This fullyintegrated approach is compatible with established silicon-on-insulator (SOI) fabricationtechniques and constitutes a significant step toward harnessing plasmonic functionalitywithin SOI photonic circuits