Abstract

Second-harmonic generation is a sensitive probe of surfaces and thin films. However, it is difficult to recognize structures of low symmetry. For example, distinction between anisotropy and chirality is nontrivial [1]. Azimuthal rotation of the sample about surface normal is sensitive to anisotropy. However, for focused beams, sample anisotropy and inhomogeneity can lead to similar rotation patterns. Here, we complement azimuthal rotation with polarization measurements (Fig. 1) to study thin films of low symmetry. Our technique does not rely on the absolute levels of different second-harmonic signals and is limited only by the accuracy of single polarization measurements.

© 1998 IEEE