Abstract
A resonant "incoherent" rectification process is presented relying on the excitation of surface plasmons on a nanostructured metal surface. Excitation of gold and silver films with 800-nm femtosecond laser pulses results in the emission of terahertz radiation with an angle-dependent efficiency and an approximately third-order power dependence. It is shown that the source of this terahertz pulse generation is the surface-plasmon-assisted multiphoton ionization and ponderomotive acceleration in the evanescent field of the surface plasmon. Simple models are used to understand the forces and dynamics near the surface.
| Original language | English |
|---|---|
| Pages (from-to) | 2470-2480 |
| Number of pages | 10 |
| Journal | Optics Express |
| Volume | 17 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 16 Feb 2009 |
Keywords
- evanescent wave acceleration
- optical rectification
- charge transfer
- emission
- films
- photoemission
- spectroscopy
- multiphoton
- excitation