SiO2/CdTe nanocomposites were prepared in thin film form on quartz substrate using a multi-target dc magnetron sputtering system. The films were deposited at high pressure (similar to 15 Pa) with deposition temperature ranging from 240 to 260 K. The films were characterized by microstructural studies and phase modulated spectroscopic ellipsometry along with optical transmittance measurements. The ellipsometric spectra were recorded in the wavelength range of 300-1200 nm. The spectra were fitted theoretically with an appropriate model assuming a realistic sample structure. Variations of refractive index, extinction coefficient and dielectric constant with wavelength have been derived. (C) 2009 Elsevier B. V. All rights reserved.