  We have measured polarized spectra of Raman scattering, infrared and optical
transmission of NaV_2O_5 single crystals above the temperature of the
spin-Peierls transition Tsp=35 K. Some of the far-infrared (FIR) phonon lines
are strongly asymmetric, due to the spin-phonon interaction. In addition to the
phonon lines, a broad band was observed in the c(aa)c Raman spectrum and in the
E||a FIR transmission spectrum. A possible origin of these bands is discussed.
The absorption band at 10000 cm-1 1.25 eV is attributed to vanadium d-d
electronic transitions while the absorption edge above 3 eV is supposed to
correspond to the onset of charge-transfer transitions.
