Simple model for the polarization effects in tip-enhanced Raman spectroscopy

The paper addresses the polarization properties of tip enhanced Raman spectroscopy (TERS) through an experimental study on (001)- and (111)-oriented crystalline Si samples and quantitatively describes them by using a simple phenomenological model. The model, conceptually similar to that used in surface-enhanced Raman scattering (SERS), is based on the introduction of a phenomenological tip-amplification tensor accounting for the interaction of the tip with the electromagnetic field. It was found to be in a good agreement not only with our experimental data but also with the measurements and numerical simulations of other groups.