Abstract

Optical second harmonic generation (SHG) is a surface and interface probe useful in environments as diverse as ultrahigh vacuum (UHV), electrochemical cells, atmospheric pressure reactors, and solid-solid interfaces. This wide applicability is due to the ability of visible or near-visible light to reach these various interfaces. The interface sensitivity arises since for centrosymmetric media, the second order nonlinear susceptibility is non-zero only where the centrosymmety is broken, ie. at interfaces. A recent review article documents a wide range of applications of this technique.¹

© 1989 Optical Society of America