Abstract

Second harmonic generation (SHG), has often been used to study structural phase transitions in solids, in particular the phase transitions from a non-centrosymmetric to a centrosymmetric phase, as it is extremely sensitive to this. We show here that the sensitivity of SHG to the spatial fluctuations of the order parameter allows one to study the details of a phase transition from a centrosymmetric to another centrosymmetric phase and to distinguish the contributions to the SHG intensity from the bulk and from subsurface layers of a crystal.

© 1998 IEEE