Abstract

Detection and characterization of molecular adsorbates is of great interest in surface science. Second-harmonic generation with its high intrinsic surface specificity has developed into a powerful tool for adsorbate analysis in recent years. Within the model of the "polarization sheet" the theory of the second-harmonic (SH) process for coverages of monolayer dimension is well established for a variety of geometrical configurations.^1–3 Similar to the procedure in linear optics, angle-of-incidence dependent complex phase factors replace the usual nonlinear Fresnel factors in total reflection (TR) geometry. In contrast to the transmission geometry the SH emission in TR geometry occurs noncollinearly with the reflected fundamental (Fig. 1). This angular shift is of considerable practical advantage because it facilitates the detection of small SH signals.

© 1991 Optical Society of America