Vibrational sum-frequency spectroscopy is a powerful tool for the study of interfaces, but its application has hitherto mainly been limited to static structure. This contribution demonstrates how the considerably improved stability of state-of-the-art lasers and parametric generators can be exploited to study the evolution of interfacial structure continuously for several hours. By sequential wavelength tuning and automated control of spatial beam overlap at the target, amplitude changes of sum-frequency resonances in widely spaced infrared regions can be probed. This offers great advantages for the study of the synchronism of molecular processes at interfaces.
Simon Schrödle and Geraldine L. Richmond, "Sequential Wavelength Tuning: Dynamics at Interfaces Investigated by Vibrational Sum-Frequency Spectroscopy," Appl. Spectrosc. 62, 389-393 (2008)