Plasmon resonant absorption and third-order optical nonlinearity in Ag–Ti cosputtered composite films

Abstract

A series of Ag/titanium oxide composite films with Ag atom concentration of 28%–82% were prepared by cosputtering technique. The scanning electron microscopy and the x-ray photoelectron spectroscopy studies reveal that metallic Ag nanoparticles with a size of 20–50nm disperse in titanium oxide. The plasmon resonance absorption peak of the embedded Ag nanoparticles shifts to about 860nm at Ag atom concentration of 42%, the nonlinear absorption coefficient βeff and the nonlinear refractive index γ are −1.4×105cm∕GW and 3.8cm2∕GW, respectively, which were measured by the Z-scan technique at 790nm with a peak irradiance of 1.8GW∕cm2. The corresponding third-order susceptibility χ(3) is about 4.7×10−7esu.

Enhanced photo-response of thin-film structures with nanocrystals

“…These results could be explained by the high quality of nanostructures (the overall emission is proportional to the quantity of luminescent LiF nanocrystals) and by the nanocrystal purity with metal excess collection in their boundaries regions. We measured nonlinear optical (NLO) effects for standard films (1), nanostructures (2,3) and TFIs (4) containing c-oriented CdS nanocrystals of defined sizes, as reported in Fig. 4.…”

“…Semiconductor and metal nanocrystals formed in dielectric layers are being extensively studied because of ultrafast optical nonlinearities [1,2] and specific photo-response due to metal content [2,3]. The local electric field inside and near metal nanoparticles is greatly enhanced due to the resonant absorption of surface plasmons, and it leads to a strong absorption, third-order susceptibility and subpicosecond response.…”

Large third-order optical nonlinearity in coupled Au–Ni–Au composite nanorods

“…Noble metal dielectric composite films [4,5] and nanostructures [6,7] have been widely studied due to their large third-order nonlinear optical susceptibility enhanced by surface plasmon absorption and localized electrical field. To obtain large optical nonlinearity at certain wavelength, different types of structures, such as nanoparticles [8], triangular prisms [9] and nanorods [10], have been studied.…”

Microstructure and multiphoton luminescence of Au nanocrystals prepared by using glancing deposition method

“…Films with large third-order optical nonlinearity and other optical properties have attracted much attention [4][5][6] owing to their applications in numerous aspects of physics and biology [7], such as optical polarizers [8], high birefringence biaxial films [2], thin-film wave plates [9], magnetic storage media [10,11], nanoemitters [12], and actuators [13]. The photoluminescence (PL) from the films can be adjusted by controlling their microstructures, which includes rods [3], spheres [14,15], plates [16], zigzags [3,17], pillars [18], chevrons [11,19], spirals [20], and Y shapes [21].…”