Abstract

The potential effect on optical second harmonic generation from a metallic electrode surface is studied. At the fundamental wavelength of 1064 nm on Ag(111), we found that the dominant effect of the applied potential is a quasilinear variation of the perpendicular surface contribution from a = +1 to a = −9 for a potential variation of 1.3 V. The absolute value of the signal and its angular dependence are in very good agreement with the theory of SHG from metals. Although the effect can be phenomenologically explained by a large effective third-order susceptibility, the variation of the perpendicular nonlinear contribution is actually related to the modification of the surface electronic distribution.¹

© 1990 Optical Society of America