Surface plasmon propagation in microscale metal stripes

Addressing the fundamental question of miniaturization of light guiding and routing towards nanoscale optics, we study experimentally surface plasmon propagation in silver and gold thin films of finite widths in the micromete r range. Spatially confined excitation of surface plasmons is realized by a prism coupling arrangement involving an opaque aluminum screen for a disti nct separation of excitation and propagation (measurement) region. The surf ace plasmon propagation length as a function of film widths is measured by detecting stray light due to surface plasmon scattering with a conventional optical microscope. (C) 2001 American Institute of Physics.