“…Binary TiO 2 -SiO 2 coatings cover a wide range of achievable refractive index [6,7] from approximately 1.45 to 2.55 because of the large difference in refractive index of the two compounds. A large number of deposition techniques including electron beam evaporation [8], sputtering [9], pulsed laser deposition [10], sol-gel [11,12,13] and chemical vapor deposition [14] have been used to prepare the binary TiO 2 -SiO 2 coatings. However, most reports deal with these types of thin films on an empirical basis, without correlating the actual values of the optical parameters with the type of thin film microstructure and the composition.…”