NEAR-FIELD RAMAN SPECTRAL MEASUREMENT OF POLYDIACETYLENE

Two-dimensional near-field Raman spectra and topographic images of the polydiacetylene surface are measured simultaneously by using a near-f ield Raman spectrometer, The spectra (located 100 nm apart) have diffe rent spectral features. The peak intensity ratio of two C=C peaks at 1 520 and 1457 cm(-1) does not correlate with the topographic image and shows differences in the subwavelength scale. These differences can be interpreted as spatial differences in the number of successive bonds on the polydiacetylene surface. In contrast, the near-field Raman inte nsity of the C=C bond at 1457 cm(-1) correlates strongly with the topo graphic image. This phenomenon can be interpreted as a change in the e fficiency of collecting Raman scattering light.