Ellipsometric and spectroscopic investigations of Hf1-xZrxO2 thin films were performed. Dispersion dependences of refractive indices and extinction coefficients in the wavelength interval 0.2-0.7 mu m were obtained by optical-refractometric synthesis of absorption spectra. Optical-refractometric relation is applied to describe the dispersion of the refractive indices. Compositional behaviour of optical pseudogap and refractive indices of HfO2-ZrO2 thin films is studied. (c) 2004 Elsevier B.V. All rights reserved.