Optical Characterization of Ag0 and TiO2 Nanoparticles
Abstract
In recent years, the development of metal material structures has brought a new horizon on the development of Metal Dielectric or Plasmonic Photonic Crystals. They involve the use of metals with very small dimensions, often nanodimensions, where metals exhibit a very distinctive behavior as compared to their bulk counterpart. In this paper we study the physical and optical properties of the basic elements of those structures, in particular in thin films. We report results of chemical synthesis and optical behavior for several material samples: silver particles of 2-10 nm size obtained by reduction of Ag+, silica spheres SiO2 in the range of 200-400 nm size, silica spheres with silver nanoparticles SiO2-Ag0, and TiO2 nanoparticles obtained by the sol-gel method. In each case, the material morphology was examined by transmission electron microscopy (TEM), while their physical properties were studied by means of photoluminescence. Two different excitation wavelengths, 320 and 380 nm, were employed and the luminescence emission in the range 400-550 nm was observed. Their optical properties were evaluated using a typical Z-scan technique. This allowed us to easily obtain the nonlinear optical behavior of the samples (Kerr nonlinearity). In our setup, non linear measurements could be achieved using two different laser systems such as He-Ne cw and a Nd-YAG pulsed laser. Our results show a positive nonlinear refractive index for Ag0 nanoparticles. The advantage of the material synthesis is that no sophisticated equipment is required to develop the nanoparticles. Work is underway towards the development of all-optical photonic devices using our nanoparticles.
- Publication:
-
6th Ibero-American Conference on Optics (RIAO) 9th Latin-American Meeting on Optics, Lasers and Applications (OPTILAS)
- Pub Date:
- April 2008
- DOI:
- 10.1063/1.2926926
- Bibcode:
- 2008AIPC..992..553E
- Keywords:
-
- 78.67.-n;
- 81.20.Fw;
- 42.65.-k;
- Optical properties of low-dimensional mesoscopic and nanoscale materials and structures;
- Sol-gel processing precipitation;
- Nonlinear optics