Resonant and nonresonant Raman scattering measurements have been obtained from very thin (27 Å to 1 μ) films of long chain organic molecules and polymers using multilayered integrated optics. The increased optical field intensity within the film together with an increase in scattering volume enable high signal/noise spectra to be obtained. Investigation of a single cyanine dye monolayer using the Resonance Raman effect has revealed frequency shifts of the quinoline in plane C—C and C—N stretching modes at 1392 and 1366 cm−1 resulting from intermolecular adhesive forces at the film-Corning glass interface. Bandwidth broadening of these modes indicates a distribution of chromophore environments at the glass surface possibly reflecting the heterogeneity of surface binding sites.
J. F. Rabolt, R. Santo, and J. D. Swalen, "Raman Measurements on Thin Polymer Films and Organic Monolayers," Appl. Spectrosc. 34, 517-521 (1980)