Optical resonant absorption and third-order nonlinearity of (Au,Ag)–TiO2 granular composite films

• Published in: Journal of physics. D, Applied physics Vol. 38; no. 3; pp. 389 - 391
• Main Authors: Wang, Ququan, Wang, Shufeng, Hang, Wentao, Gong, Qihuang
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 07.02.2005; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Optical properties of nanoscale materials and structures; Physics; Gold; Annealing; Inorganic compounds; Transition element compounds; Nanostructures; Granular structure; Nonlinear optical susceptibility; Titanium oxides; Silver; Composite materials; Absorption spectra; Nonlinear optics; Radiofrequency sputtering; Ultrafast process
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/38/3/006

The nanosized (Au,Ag)-Ti three-component granular composite films on glass substrates were prepared using an rf co-sputtering method, and the deposited films were annealed in air. The optical absorption and the ultrafast third-order nonlinearity of the (Au,Ag)-TiO2 films annealed at different temperatures were investigated. The composite film annealed at 600 deg C exhibits strong resonant absorption at wavelengths of 400 and 670 nm. The ultrafast third-order nonlinear optical susceptibility at 820 nm of the phase separated (Au,Ag)-TiO2 composite film is measured to be 7.4 X 10-9 esu. This is about 70% larger than that of the Au-TiO2 composite film.