Far-infrared vibrational modes of polycrystalline saccharides

We have measured the temperature dependence of the far-infrared vibrational modes of polycrystalline saccharide molecules in the frequency range 0.1-3.0 THz using a time-resolved terahertz spectroscopy system. Coherent measurement of the transmitted terahertz electric fields showed distinct absorption features, in both monosaccharides and disaccharides, originating from inter- and intra-molecular vibrational modes. These results show that far-infrared absorption features are highly sensitive to the structure and spatial arrangement of molecules. Furthermore, we demonstrate a broad band terahertz spectroscopy system that can be used to probe molecular interactions up to higher frequencies (>6.0 THz). (C) 2004 Elsevier B.V. All rights reserved.