Spectroscopic ellipsometry measurements were employed to characterize nanowhisker structures grown by molecular-beam epitaxy on Si (111) substrates. Small clusters of gold deposited on the Si surface were used as the seeds for nanowhisker (NW) growth. Nitridation procedure was carried out for passivation to create ambient protection. Optical properties and thickness of passivation film were studied on satellite-speciment-speciment Si (111). By means of spectroscopic ellipsometry in the range of 1.5-4.77 eV, a) lateral optical inhomogeneity of the nanowhisker layer (NWL), b) substantial differing of optical properties of the NWL from those of single-crystal Si, and c) dependences of optical properties of the NWL on their length and on both metallization and nitridation procedure were revealed. Explanation of appearance in ellipsometric spectra of ""gigantic"" NWL absorption in the range of almost complete transparency of crystal Si was been suggested.

Key words: metamaterials, nanostructures, whiskers, optical properties, spectroscopic ellipsometry.