Enhancement factor averaging and the photostability of probes in SERS vibrational pumping.

The technique of temperature dependent vibrational pumping in surface enhanced Raman scattering (SERS) has been recently demonstrated as a promising new tool to estimate SERS cross-sections. In this paper we expand on the previous developments and study several details around the implementation and physics of the vibrational pumping technique in SERS. Here we concentrate on two specific aspects related to: (i) the different averaging properties (over the distribution of enhancements) of the Stokes and anti-Stokes signals in the pumping regime; and (ii) the role of the finite photostability of the probes. The fact that the anti-Stokes signal is averaged differently from the Stokes counterpart leads to some unique phenomena in Raman spectroscopy that can only be observed under the conditions of vibrational pumping in SERS.