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Absorption spectra of sixteen polymers have been examined using terahertz (THz) time-domain spectroscopy system in THz frequency range (0.1 - 3 THz). All the experimental data showed a characteristic wide absorption peak at the frequencies around 2.5 THz accompanied by smoothly decreasing of refraction (except "transparent" polymers). Such behavior could be described by a modified Debye model. We also tried to clarify the impact of flexibility, polymerization, crystalline degree and number of monomer end groups on polymer dielectric properties. We suggest that the absorption mechanism in spectral range lower than 3 THz is related with relaxation and amorphous state of polymers.

The terahertz time-domain and Raman spectra of corticosteroid hormones in the region of low-frequency infrared vibrations have been measured. On the ground of quantum chemical calculations of the frequencies and normal modes the assignments of vibrational bands in the THz-spectra are performed.