Abstract

Three-wave mixing, primarily in the form of second-harmonic generation (SHG), has been demonstrated to be a sensitive and versatile probe of the properties of surfaces and interfaces of centrosymmetric media.¹ The power of the second- order nonlinear optical effects derives from the fact that the process is (dipole) forbidden within the bulk of centrosymmetric media, but not in the asymmetric surface or interfacial region. Thus, one has a purely optical technique, with its concomitant advantages of high spectral and temporal resolution and wide range of applicability, that displays a degree of surface sensitivity characteristic of electron spectroscopy. In this paper, we describe some recent advances in and new applications of this nonlinear spectroscopic method.

© 1988 Optical Society of America