TERS

Tip Enhanced Raman Scattering (TERS, nano-Raman) is the technique for enhancement of weak Raman signals and for super-resolution Raman imaging with spatial resolution ~10 nm. Nano-Raman imaging provides unique insights into sample structure and chemical composition on the nanometer scale.

In TERS, a sharp metal probe (nano-antenna) is used to localize and enhance optical field at the tip apex. The light enhancement is typically reached when excitation laser light is in resonance with localized surface plasmon at the end of the TERS probe. Enhancement of electromagnetic field (light) intensity on the TERS probe apex can reach many orders of magnitudes. In TERS mapping the sample is scanned with respect to the nano-antenna; the enhanced Raman signal localized near the probe apex is measured resulting in Raman maps of the sample surface with nanometer scale resolution.