  Infrared reflectance of alpha'-NaV2O5 single crystals in the frequency range
from 50 cm-1 to 10000 cm-1 was studied for a, b and c-polarisations. In
addition to phonon modes identification, for the a-polarised spectrum a broad
continuum absorption in the range of 1D magnetic excitation energies was found.
The strong near-IR absorption band at 0.8 eV shows a strong anisotropy with
vanishing intensity in c-polarisation. Activation of new phonons due to the
lattice dimerisation were detected below 35K as well as pretransitional
structural fluctuations up to 65K.
