Abstract
We use two-beam second-harmonic generation to separate the surface (electric dipole origin) and bulk (magnetic dipole and electric quadrupole origin) contributions to the second-order nonlinear optical response of an isotropic gold film. The bulk response is unambiguously observed and explained by momentum damping of electrons in a free-electron model. Although bulk effects could be enhanced by inhomogeneous local fields in metal nanostructures and have been used to model second-harmonic generation from metamaterials [Y. Zeng et al., Phys. Rev. B 79, 235109 (2009)], we find that surface effects dominate the nonlinearity. Our quantitative results for the surface and bulk parameters set the baseline for future descriptions of the second-order response of nanostructured metals.
| Original language | English |
|---|---|
| Article number | 233402 |
| Number of pages | 4 |
| Journal | Physical Review B: Condensed Matter and Materials Physics |
| Volume | 80 |
| Issue number | 23 |
| DOIs | |
| Publication status | Published - 2009 |
| MoE publication type | A1 Journal article-refereed |
Keywords
- gold
- metallic thin films
- metamaterials
- nanostructured materials
- nonlinear optics
- optical harmonic generation
- optical materials