Vibrational Sum Frequency Generation Spectroscopy
Sum frequency generation (SFG) is one of the second-order nonlinear optical processes in which two incident photons are up-converted to one photon having the energy (frequency) of the sum of these two inputs (Shen in The Principles of Nonlinear Optics. John Wiley & Sons, Inc, 1984). Because this optical process is forbidden in the region having inversion symmetry under the dipole approximation, the SFG signal is not generated in the bulk media but arises only from the interface region. Therefore, SFG provides interface-selective information.
KeywordsInterface-selective nonlinear spectroscopy Vibrational spectroscopy Heterodyne-detection Time-resolved measurement Liquid interfaces
- 1.Shen, Y.R.: The Principles of Nonlinear Optics. John Wiley & Sons, Inc. (1984)Google Scholar