Long-range surface-plasmon modes in silver and aluminum films

TLDR

The resonance is caused by excitation of long‑range surface‑plasmon modes on both sides of thin silver and aluminum films, as originally described by Sarid. We observed a sharp minimum in attenuated total reflectivity of thin metal films and found that the resonance angular widths in silver and aluminum are more than ten times narrower than those of the Kretschmann mode. Citation: Phys.

Abstract

We report the first observation to our knowledge of a sharp minimum in the attenuated total reflectivity of a thin metal film between index-matching layers. The resonance is due to the excitation of the long-range surface-plasmon mode on both sides of the thin metal films, as originally discussed by Sarid [Phys. Rev. Lett. 47, 1927 (1981)]. The angular widths of the observed resonance in silver and aluminum films are both reduced by over an order of magnitude relative to that associated with the Kretschmann excited mode.