Figure 11.

(a) Sketch of the 2C-SFG experiment on the gold nanopillars electrochemically grown on a gold or platinum surface in $ssp$-polarization scheme. Samples are functionalized with dodecanethiol (DDT) molecules. The electric yield enhancement of the transverse (TM) and longitudinal (LM) surface plasmon modes is depicted in green and red, respectively. (b) UV-Visible absorbance spectra of the sample with a gold substrate. (c) Comparison between the SFG spectra of the DDT/Au nanopillars/Pt (left) or Au (right) interfaces (dark blue) with respect to the DDT/Pt (left) or Au (right) interfaces (light blue). Figure panel is adapted from reference [77].