  Spectral ellipsometry studies of the optical functions, first observation of
photoluminescence and low frequency dielectric permittivity investigations were
performed in ferroelectric - multiferroic TbMnO3 single crystals. The main
attention was paid to electronic band structure, nature of the main optical
transitions and unusual behavior of the dielectric permittivity in the region
of the sharp narrow temperature maximum, associated with ferroelectric phase
transition. It was found that magnitude of the permittivity maximum decreases
strongly with frequency, whereas position of maximum is frequency independent.
Observed features of polarization response can be described satisfactorily in
the frame of on the basis of the Landau-Khalatnikov theory for critical
relaxation polarization
