Surface studies using optical second-harmonic generation

Optical second-harmonic generation (SHG) from a system of two centrosymmetric media arises largely from the interface between the media. This interfacial-specificity allows SHG to be a useful probe of a variety of surface properties including: surface-adsorbate coverage, adsorbate orientation and arrangement on the substrate, the site of adsorption, and surface structural symmetry. The versatility and sensitivity of SHG as a surface probe is illustrated with examples drawn from recent work (Tom et al., 1983; Heinz et al., 1983; Shank et al., 1983).