The effects of probe boundary conditions and propagation on nano-Raman spectroscopy.
Raman spectra obtained in the near-field, with collection of the Raman-shifted light in reflection, show selective enhancement of vibrational modes. We show that the boundary conditions for an electric field near a metal surface affect propagation of the reflected signal and lead to this selection. The enhancement of certain Raman forbidden vibrations is explained by the presence of an electric field gradient near the metal-apertured fibre probe.
Hallen
H D
HD
Physics Department, North Carolina State University, Raleigh, USA.
Ayars
E J
EJ
Jahncke
C L
CL