Tip-Enhanced Sum Frequency Generation for Molecular Vibrational Nanospectroscopy.

ABSTRACT: Vibrational sum frequency generation (SFG) is a nonlinear spectroscopic technique widely used to study the molecular structure and dynamics of surface systems. However, the spatial resolution achieved by far-field observations is constrained by the diffraction limit, obscuring molecular details in inhomogeneous structures smaller than the wavelength of light. To overcome this limitation, we developed a system for tip-enhanced SFG (TE-SFG) spectroscopy based on a scanning tunneling microscope. We successfully detected vibrational TE-SFG signals from adsorbed molecules on a gold substrate under ambient conditions. The phase analysis of interferometric SFG spectra provided information on molecular orientation. Furthermore, the observed TE-SFG signal was confirmed to originate from a highly lo

SUBMITTER: Sakurai A 

PROVIDER: S-EPMC12023042 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature