TiO 2 nanoceramic films prepared by ion beam assisted evaporation for optical application

Abstract

A TiO 2 nanoceramic film was prepared as an alternative absorber layer for infrared thermal detectors. The TiO 2 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 TiO 2 films on polycarbonate (PC) substrates. The nonlinear refraction index was measured to be of the order of 10 −8 cm 2 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 TiO 2 films exhibited higher linear refractive indices, obvious red-shifts and narrower absorption bands in the near-IR region.