Optical absorptive response of platinum doped TiO2 transparent thin films with Au nanoparticles

In this paper different optical absorption bands associated to the surface plasmon of resonance of a nanoparticle containing sample were achieved by a sol–gel processing route. We study the linear and nonlinear optical absorptive properties of a titanium dioxide thin film with superficial Au nanoparticles. A chaotic behavior related with modification of the optical absorption by a multi-wave mixing interaction was investigated. A characteristic Mandelbrot group tendency was used to describe the possibility of a resulting absorptive response. The analysis of the observations showed that an excitation at 488 nm wavelength in the nanocomposite can originate a measurable change in the absorptive properties for the propagation of optical beams at 532 nm and at 650 nm. However, the inhibition of this condition exhibited by the film can be obtained by the shift of its plasmonic response. It is considered that the near resonance participation of the Au nanoparticles is mainly responsible for avoiding the photodarkening contribution to the optical absorptive response of the sol–gel TiO₂ film with embedded Au nanoparticles. Potential applications of the samples are proposed for development of optical sensors or transparent thin films for filtering functions.