APPLICATION OF THE SUM-FREQUENCY GENERATION TO THE VIBRATIONAL SPECTROSCOPY OF A LANGMUIR-BLODGETT-FILM

In this paper, we calculate the sum-frequency generation (SFG) signal for molecules adsorbed on a surface. The expression is established as a function of the molecular microscopic constants and for different polarization combinations of the input beams. Next, this result is applied to reproduce simultaneously experimental SFG spectra of pentadecanoic acid molecules on a water surface obtained for different polarizations of the input beams. From the fit, we have been able to determine unambiguously the microscopic parameters of the adsorbate. © 1995 The American Physical Society.