We de
monstrate Fourier transfor
m infrared nanospectroscopy (nano-FTIR) based on a scattering-type scanning near-field optical
microscope (s-SNOM) equipped with a coherent-continuu
m infrared light source. We show that the
method can straightforwardly deter
mine the infrared absorption spectru
m of organic sa
mples with a spatial resolution of 20 n
m, corresponding to a probed volu
me as s
mall as 10 zeptoliter (10
鈥?0 L). Corroborated by theory, the nano-FTIR absorption spectra correlate well with conventional FTIR absorption spectra, as experi
mentally de
monstrated with poly(
methyl
methacrylate) (PMMA) sa
mples. Nano-FTIR can thus
make use of standard infrared databases of
molecular vibrations to identify organic
materials in ultras
mall quantities and at ultrahigh spatial resolution. As an application exa
mple we de
monstrate the identification of a nanoscale PDMS conta
mination on a PMMA sa
mple.
Keywords:
Infrared nanospectroscopy;
mical+identification&qsSearchArea=searchText">chemical identification;
mers&qsSearchArea=searchText">polymers;
microscopy&qsSearchArea=searchText">near-field microscopy;
s-SNOM;
FTIR