Optical Nonlinearity of Mesoporous Silica Thin Films Embedded with Gold Nanoparticles

Abstract

The mesoporous silica thin films (MSTFs) synthesized by evaporation-induced self-assembly were loaded with gold nanoparticles (GNPs). The TEM and XRD characterizations showed that the template of MSTF possessed a well-ordered mesostructure, and GNPs can be well crystallized in the thin film by neutralization and hydrogen-reduction reactions. The z-scan technique was used for studying the nonlinear optical properties of the GNPs/MSTF nanocomposite. The results showed that this kind of material was possessed of a relatively feeble nonlinear absorption but an obvious nonlinear refraction. The nonlinear refractive index was estimated to be 7.9 × 10⁻¹¹ cm²/W and the theoretical fitting well matched with the measured data.

Keywords:

• Nanocomposites
• gold nanoparticles
• thin films
• nonlinear refractive index

Acknowledgments

This work is supported by the Advanced Research Foundation of National University of Defense Technology grant JC11-02-19, and the National Natural Science Foundation of China grant 11104349 and 11104347.