ATR-SNOM-Raman spectroscopy

In this study, (1) an ATR-SNOM-Raman equipment was built to obtain topography and SNOM images simultaneously, (2) Raman spectra from copper phthalocyanine (CuPc) were obtained with 600 s without using the resonance effect, (3) the optimum conditions to excite the LSP (Localized Surface Plasmon) on the Ag island films were found, (4) the Raman signal from CuPc (1.5 nm) was enhanced by a factor of ca. 300 using the Ag island film (5 nm), which gives 36 counts/s for ca. 7000 molecules assuming a sampled volume of φ 50 nm×1.5 nm thickness, and enables us to obtain the Raman spectra in 2 s. At last, (5) SNOM-Raman signal arises from the surface < ca. 2 nm similar to a localized SPP field.