Achievement

Coupling light into and out of waveguiding structures is of interest in optoelectronics and on chip waveguiding. IGERT trainees have demonstrated nanoparticle mediated coupling of free space optical waves into and out of the surface plasmon modes of a metallic film as an effective way to locally excite and interrogate surface plasmons. Nanosteps, sub-10-nm gaps between metallic films of differing thickness, can also launch and detect surface plasmons. We have probed both types of structures to locally launch propagating surface plasmon waves and probe their properties. Nanoparticle-launched surface plasmons emerge as two lobes of nominally 90 degree angular width, propagating along the direction of incident polarization.