Surface plasmon mediated interference phenomena in low-Q silver nanowire cavities

Optical excitation of surface plasmons in wet-chemically grown monocrystalline silver nanowires (∼100 nm diameter and up to a few tens of micrometers length) is studied by broadband imaging spectroscopy. Surface plasmons excited by an incident light beam in the so-called Kretschmann-Raether configuration give optical interference phenomena in the spectral domain. These spectral oscillations are interpreted in terms of Fabry-Perot cavity modes for surface plasmons in silver nanowires and allow for a direct experimental determination of the surface plasmon group velocity and cavity losses.