Zirconia thin films were deposited on silicon (1 0 0) and quartz substrates using pulsed laser deposition. Phase formation in zirconia films was monitored as a function of substrate temperature (473-973 K) and oxygen partial pressure (0.001-1 Pa). Volume fraction of tetragonal zirconia is determined from X-ray diffraction and Raman analysis. Tetragonal volume fraction of zirconia films varies from 10 to 76% for different substrate temperature and oxygen partial pressure. Zirconia films show a good transparency in the visible region, except for the films deposited at 473 K and at 0.002 Pa. The band gap values and refractive index of the films are discussed in relation with the microstructure and phase composition of the zirconia films as well as with 8 mol% yttria stabilised zirconia films. (C) 2012 Elsevier B. V. All rights reserved.