NEAR-FIELD 2ND-HARMONIC GENERATION FROM A ROUGH METAL-SURFACE

Local second-harmonic generation (SHG) from a rough metal surface has been measured using a near-field optical microscope. The dependence of the SH signal on the tip-surface distance for excitation with S-and P -polarized light shows the presence of evanescent SH field components. With excitation by S-polarized light the SHG over the rough surface i s found to be strongly related to surface topography. For P-polarized light excitation, local enhancement of SH emission have been observed that may be attributed to SH field localization.