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.