Surface-plasmon-enhanced multiphoton photoelectric emission from thin silver films

Abstract

We report the enhancement of multiphoton photoelectric emission, from a thin silver film, by surface plasmons excited at the single-metal-vacuum interface. The surface plasmons are resonantly pumped by femtosecond laser pulses in the Kretchmann attenuated-total-internal-reflection configuration. A quantum yield approaching 2 x 10(-8) at a photon fluence of 10 MW/cm (2) from a two-photon process was observed, which is 5 x 10(3) higher than that of the bulk emission measured for the same film at the same power fluence.