Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1541474 | Optics Communications | 2006 | 7 Pages |
Abstract
The electromagnetic field distribution on an illuminated rough gold surface has been investigated by apertureless scanning near-field optical microscopy. The sample consists of an alumina substrate with a variable gold coverage ranging from 0 to 30 monolayers (ML). For such small thicknesses, the metal layer is not continuous but exhibits a certain roughness. We have studied the influence of this thickness on the electromagnetic field localization on the surface. For a gold coverage smaller than 10 equivalent monolayers, the electromagnetic field is almost uniform on the surface. For 10 and 14Â ML, the field becomes inhomogeneous and isolated, localized peaks start to be visible. The width of the peaks is smaller than 50Â nm. Above 14Â ML, strong variations are apparent everywhere on the sample. Their amplitude tends to saturate beyond 24Â ML. A complete statistical study of the sample (standard deviation, Fourier analysis) is performed.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
L. Aigouy, V. Mathet, P. Beauvillain,