Surface-plasmon field-enhanced multiphoton photoelectric emission from metal films
- Brookhaven National Laboratory, Upton, New York 11973 (US)
We report a study of surface-plasmon-mediated multiphoton photoelectric emission from thin films of Ag, Au, Cu, and Al. The experiments were performed in the Kretchmann attenuated-total-internal reflection geometry while the excitation source was an unamplified femtosecond colliding-pulse mode-locked ring laser. Contrast to the electron emission obtained by irradiating the laser on a metal surface, electron yield increases by several orders of magnitude with fairly high quantum efficiency, is observed when photons are coupled to the surface-plasmon modes of these films. Although the photon absorption reaches its maximum when the reflectivity exhibits a deep minimum at the surface-plasmon resonance angle, it is found that the maximum electron yield occurs at a slightly different angle than the reflectivity dip. The results of these measurements favor the field-density calculations using the Fresnel equations. The width of the electron temporal profile, measured utilizing this nonlinear photoelectric effect, however, fails to show the narrowing commensurate with the higher-order nonlinearity.
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 5889235
- Journal Information:
- Physical Review, B: Condensed Matter; (USA), Vol. 43:11; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
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