Surface polariton dispersion measurement by Raman scattering excited in total reflection condition

We report the first measurement of phonon surface polariton (s.p.) dispersion by a non-forward Raman scattering geometry. The Raman scattering from surface modes was excited by the evanescent electromagnetic wave produced by total reflection at the interface between two transparent media. This Raman Scattering excited in condition of Total Reflection, RSTR, has been applied to the NaClO₃-sapphire interface for studying the surface polariton dispersion in the gap between the TO frequency at 966 cm^-1 and the LO frequency at 983 cm^-1 of sodium chlorate. Comparison is made between the experimental and theoretical dispersion curves.