A. Tadjeddine, Spectroscopic investigation of surfaces and interfaces by using infrared-visible sum and difference frequency generation, SURF REV L, 7(4), 2000, pp. 423-436
The nonlinear optical techniques of visible-infrared sum (SFG) and differen
ce (DFG) frequency generation are addressed as a vibrational probe of surfa
ces and interfaces between media of inversion symmetry.