Au/TiO2/SiO2 sandwich multilayer composite films with large nonlinear optical susceptibility

• Published in: Optical materials Vol. 27; no. 8; pp. 1433 - 1437
• Main Authors: Yu, S.W., Liao, H.B., Wen, W.J., Wong, G.K.L.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2005; Elsevier Science
• Subjects: Exact sciences and technology; Fundamental areas of phenomenology (including applications); Metal particles; Nonlinear optics; Nonlinearity; Optical susceptibility, hyperpolarizability; Optics; Physics; Size; 42.65.−k; Nonlinearity; 78.66.−w; Metal particles; Size; 72.80.Tm; Gold; 78.66.-w Metal particles; Binary compounds; Metal particle; Nonlinear optical susceptibility; Titanium oxides; Multilayers; Composite materials; Local field; Silicon oxides; Optical properties; Degenerate four wave mixing; Visible radiation; 42.65.-k; Surface plasmon resonance; Nonlinear optics
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2004.07.017

Au/TiO2/SiO2 sandwich composite multilayer films were deposited by alternating multitarget magnetron sputtering technique. Annealing process was performed for as-growth. Au particles appeared between the layers and grew with the increasing of the annealing temperature. The surface plasmon resonance of the annealed films is around 570–590nm. The third-order nonlinear susceptibility was measured with the backward degenerate four wave mixing (DFWM) scheme at a 532nm wavelength. The calculated values of χ(3) at 532nm of the composite films are larger than 1.02×10−6esu. We assume the multilayer sandwich topology of the Au/TiO2/SiO2 composite films has greatly enhanced the local field factor f and caused a larger χ(3) which is even not measured at the wavelength near the surface plasmon resonance of the composite materials.