TiO2 nanoceramic films prepared by ion beam assisted evaporation for optical application

A TiO2 nanoceramic film was prepared as an alternative absorber layer for infrared thermal detectors. The TiO2 film was amorphous, and its grain size increased with the ion anode voltage and oxygen flow rate. Moiré deflectometry was applied for measuring the nonlinear refractive indices of TiO2 films on polycarbonate (PC) substrates. The nonlinear refraction index was measured to be of the order of 10−8 cm2 W−1 and the change in refractive index was of the order of 10−5. The linear refractive index was correlated with the porosity. Denser TiO2 films exhibited higher linear refractive indices, obvious red-shifts and narrower absorption bands in the near-IR region.