The properties of TiO2 nanoceramic films prepared by electron beam evaporation

TiO2 nanoceramic films were deposited on polycarbonate (PC) substrate by electron beam evaporation. This deposition technique is well established for producing dense and adhesive optical films. At high power, the particles arrived at the substrate with high kinetic energy, and high impact also led to low density due to porous structure. The porous TiO2 films resulted in low linear refractive index. As the film thickness increased, the surface of TiO2 films exhibited the grain growth obviously, resulting in high surface roughness. The transparent TiO2 films showed red-shift because of large grain size. Transparent materials generally have optical Kerr effect. The knowledge of nonlinear refractive index of materials is of great interest due to its potential applications in designing optical devices. Moiré deflectometry is a powerful tool for measuring nonlinear refractive index of materials. In this study, this method is applied for measuring the nonlinear refractive index of TiO2 nanoceramic films on PC substrates. The nonlinear refraction index can be measured to be in order of 10(-8) cm2 W(-1) and the change in refractive index is in order of 10(-5).